diff --git a/crates/test-programs/wasi-tests/Cargo.lock b/crates/test-programs/wasi-tests/Cargo.lock
index 004fa00ccb..d1d241ba80 100644
--- a/crates/test-programs/wasi-tests/Cargo.lock
+++ b/crates/test-programs/wasi-tests/Cargo.lock
@@ -16,9 +16,9 @@ checksum = "7709cef83f0c1f58f666e746a08b21e0085f7440fa6a29cc194d68aac97a4225"
 
 [[package]]
 name = "wasi"
-version = "0.10.2+wasi-snapshot-preview1"
+version = "0.11.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
 [[package]]
 name = "wasi-tests"
diff --git a/crates/test-programs/wasi-tests/Cargo.toml b/crates/test-programs/wasi-tests/Cargo.toml
index 53e4691bfc..64a5ca3db6 100644
--- a/crates/test-programs/wasi-tests/Cargo.toml
+++ b/crates/test-programs/wasi-tests/Cargo.toml
@@ -7,7 +7,7 @@ publish = false
 
 [dependencies]
 libc = "0.2.65"
-wasi = "0.10.2"
+wasi = "0.11.0"
 once_cell = "1.12"
 
 # This crate is built with the wasm32-wasi target, so it's separate
diff --git a/crates/test-programs/wasi-tests/src/bin/close_preopen.rs b/crates/test-programs/wasi-tests/src/bin/close_preopen.rs
index 9066f06453..9f955f44a7 100644
--- a/crates/test-programs/wasi-tests/src/bin/close_preopen.rs
+++ b/crates/test-programs/wasi-tests/src/bin/close_preopen.rs
@@ -8,17 +8,14 @@ unsafe fn test_close_preopen(dir_fd: wasi::Fd) {
 
     // Try to close a preopened directory handle.
     assert_errno!(
-        wasi::fd_close(pre_fd)
-            .expect_err("closing a preopened file descriptor")
-            .raw_error(),
+        wasi::fd_close(pre_fd).expect_err("closing a preopened file descriptor"),
         wasi::ERRNO_NOTSUP
     );
 
     // Try to renumber over a preopened directory handle.
     assert_errno!(
         wasi::fd_renumber(dir_fd, pre_fd)
-            .expect_err("renumbering over a preopened file descriptor")
-            .raw_error(),
+            .expect_err("renumbering over a preopened file descriptor"),
         wasi::ERRNO_NOTSUP
     );
 
@@ -33,8 +30,7 @@ unsafe fn test_close_preopen(dir_fd: wasi::Fd) {
     // Try to renumber a preopened directory handle.
     assert_errno!(
         wasi::fd_renumber(pre_fd, dir_fd)
-            .expect_err("renumbering over a preopened file descriptor")
-            .raw_error(),
+            .expect_err("renumbering over a preopened file descriptor"),
         wasi::ERRNO_NOTSUP
     );
 
diff --git a/crates/test-programs/wasi-tests/src/bin/dangling_symlink.rs b/crates/test-programs/wasi-tests/src/bin/dangling_symlink.rs
index bfc9095d38..f7538fc979 100644
--- a/crates/test-programs/wasi-tests/src/bin/dangling_symlink.rs
+++ b/crates/test-programs/wasi-tests/src/bin/dangling_symlink.rs
@@ -9,8 +9,7 @@ unsafe fn test_dangling_symlink(dir_fd: wasi::Fd) {
         // Try to open it as a directory with O_NOFOLLOW.
         assert_errno!(
             wasi::path_open(dir_fd, 0, "symlink", wasi::OFLAGS_DIRECTORY, 0, 0, 0)
-                .expect_err("opening a dangling symlink as a directory")
-                .raw_error(),
+                .expect_err("opening a dangling symlink as a directory"),
             wasi::ERRNO_NOTDIR,
             wasi::ERRNO_LOOP
         );
@@ -18,8 +17,7 @@ unsafe fn test_dangling_symlink(dir_fd: wasi::Fd) {
         // Try to open it as a file with O_NOFOLLOW.
         assert_errno!(
             wasi::path_open(dir_fd, 0, "symlink", 0, 0, 0, 0)
-                .expect_err("opening a dangling symlink as a file")
-                .raw_error(),
+                .expect_err("opening a dangling symlink as a file"),
             wasi::ERRNO_LOOP
         );
 
diff --git a/crates/test-programs/wasi-tests/src/bin/directory_seek.rs b/crates/test-programs/wasi-tests/src/bin/directory_seek.rs
index ab4b0dbc87..85b96e6a10 100644
--- a/crates/test-programs/wasi-tests/src/bin/directory_seek.rs
+++ b/crates/test-programs/wasi-tests/src/bin/directory_seek.rs
@@ -23,9 +23,7 @@ unsafe fn test_directory_seek(dir_fd: wasi::Fd) {
 
     // Attempt to seek.
     assert_errno!(
-        wasi::fd_seek(fd, 0, wasi::WHENCE_CUR)
-            .expect_err("seek on a directory")
-            .raw_error(),
+        wasi::fd_seek(fd, 0, wasi::WHENCE_CUR).expect_err("seek on a directory"),
         wasi::ERRNO_BADF
     );
 
diff --git a/crates/test-programs/wasi-tests/src/bin/fd_filestat_get.rs b/crates/test-programs/wasi-tests/src/bin/fd_filestat_get.rs
index d2ba27a1dd..3cff4e7221 100644
--- a/crates/test-programs/wasi-tests/src/bin/fd_filestat_get.rs
+++ b/crates/test-programs/wasi-tests/src/bin/fd_filestat_get.rs
@@ -1,5 +1,4 @@
 unsafe fn test_fd_filestat_get() {
-
     let stat = wasi::fd_filestat_get(libc::STDIN_FILENO as u32).expect("failed filestat 0");
     assert_eq!(stat.size, 0, "stdio size should be 0");
     assert_eq!(stat.atim, 0, "stdio atim should be 0");
diff --git a/crates/test-programs/wasi-tests/src/bin/file_seek_tell.rs b/crates/test-programs/wasi-tests/src/bin/file_seek_tell.rs
index 1272d4e106..a3d3711b95 100644
--- a/crates/test-programs/wasi-tests/src/bin/file_seek_tell.rs
+++ b/crates/test-programs/wasi-tests/src/bin/file_seek_tell.rs
@@ -57,8 +57,7 @@ unsafe fn test_file_seek_tell(dir_fd: wasi::Fd) {
     // Seek before byte 0 is an error though
     assert_errno!(
         wasi::fd_seek(file_fd, -2000, wasi::WHENCE_CUR)
-            .expect_err("seeking before byte 0 should be an error")
-            .raw_error(),
+            .expect_err("seeking before byte 0 should be an error"),
         wasi::ERRNO_INVAL
     );
 
diff --git a/crates/test-programs/wasi-tests/src/bin/interesting_paths.rs b/crates/test-programs/wasi-tests/src/bin/interesting_paths.rs
index 70aaae3abc..16954c92fd 100644
--- a/crates/test-programs/wasi-tests/src/bin/interesting_paths.rs
+++ b/crates/test-programs/wasi-tests/src/bin/interesting_paths.rs
@@ -14,8 +14,7 @@ unsafe fn test_interesting_paths(dir_fd: wasi::Fd, arg: &str) {
     // Now open it with an absolute path.
     assert_errno!(
         wasi::path_open(dir_fd, 0, "/dir/nested/file", 0, 0, 0, 0)
-            .expect_err("opening a file with an absolute path")
-            .raw_error(),
+            .expect_err("opening a file with an absolute path"),
         wasi::ERRNO_PERM
     );
 
@@ -39,8 +38,7 @@ unsafe fn test_interesting_paths(dir_fd: wasi::Fd, arg: &str) {
     // Now open it with a trailing NUL.
     assert_errno!(
         wasi::path_open(dir_fd, 0, "dir/nested/file\0", 0, 0, 0, 0)
-            .expect_err("opening a file with a trailing NUL")
-            .raw_error(),
+            .expect_err("opening a file with a trailing NUL"),
         wasi::ERRNO_INVAL,
         wasi::ERRNO_ILSEQ
     );
@@ -48,8 +46,7 @@ unsafe fn test_interesting_paths(dir_fd: wasi::Fd, arg: &str) {
     // Now open it with a trailing slash.
     assert_errno!(
         wasi::path_open(dir_fd, 0, "dir/nested/file/", 0, 0, 0, 0)
-            .expect_err("opening a file with a trailing slash should fail")
-            .raw_error(),
+            .expect_err("opening a file with a trailing slash should fail"),
         wasi::ERRNO_NOTDIR,
         wasi::ERRNO_NOENT
     );
@@ -57,8 +54,7 @@ unsafe fn test_interesting_paths(dir_fd: wasi::Fd, arg: &str) {
     // Now open it with trailing slashes.
     assert_errno!(
         wasi::path_open(dir_fd, 0, "dir/nested/file///", 0, 0, 0, 0)
-            .expect_err("opening a file with trailing slashes should fail")
-            .raw_error(),
+            .expect_err("opening a file with trailing slashes should fail"),
         wasi::ERRNO_NOTDIR,
         wasi::ERRNO_NOENT
     );
@@ -85,8 +81,7 @@ unsafe fn test_interesting_paths(dir_fd: wasi::Fd, arg: &str) {
     let bad_path = format!("dir/nested/../../../{}/dir/nested/file", arg);
     assert_errno!(
         wasi::path_open(dir_fd, 0, &bad_path, 0, 0, 0, 0)
-            .expect_err("opening a file with too many \"..\"s in the path should fail")
-            .raw_error(),
+            .expect_err("opening a file with too many \"..\"s in the path should fail"),
         wasi::ERRNO_PERM
     );
     wasi::path_unlink_file(dir_fd, "dir/nested/file")
diff --git a/crates/test-programs/wasi-tests/src/bin/nofollow_errors.rs b/crates/test-programs/wasi-tests/src/bin/nofollow_errors.rs
index 11fdffc034..86c6f38589 100644
--- a/crates/test-programs/wasi-tests/src/bin/nofollow_errors.rs
+++ b/crates/test-programs/wasi-tests/src/bin/nofollow_errors.rs
@@ -11,8 +11,7 @@ unsafe fn test_nofollow_errors(dir_fd: wasi::Fd) {
     // Try to open it as a directory with O_NOFOLLOW again.
     assert_errno!(
         wasi::path_open(dir_fd, 0, "symlink", wasi::OFLAGS_DIRECTORY, 0, 0, 0)
-            .expect_err("opening a directory symlink as a directory should fail")
-            .raw_error(),
+            .expect_err("opening a directory symlink as a directory should fail"),
         wasi::ERRNO_LOOP,
         wasi::ERRNO_NOTDIR
     );
@@ -20,8 +19,7 @@ unsafe fn test_nofollow_errors(dir_fd: wasi::Fd) {
     // Try to open it with just O_NOFOLLOW.
     assert_errno!(
         wasi::path_open(dir_fd, 0, "symlink", 0, 0, 0, 0)
-            .expect_err("opening a symlink with O_NOFOLLOW should fail")
-            .raw_error(),
+            .expect_err("opening a symlink with O_NOFOLLOW should fail"),
         wasi::ERRNO_LOOP,
         wasi::ERRNO_ACCES
     );
@@ -56,8 +54,7 @@ unsafe fn test_nofollow_errors(dir_fd: wasi::Fd) {
     // Try to open it as a directory with O_NOFOLLOW again.
     assert_errno!(
         wasi::path_open(dir_fd, 0, "symlink", wasi::OFLAGS_DIRECTORY, 0, 0, 0)
-            .expect_err("opening a directory symlink as a directory should fail")
-            .raw_error(),
+            .expect_err("opening a directory symlink as a directory should fail"),
         wasi::ERRNO_LOOP,
         wasi::ERRNO_NOTDIR
     );
@@ -65,8 +62,7 @@ unsafe fn test_nofollow_errors(dir_fd: wasi::Fd) {
     // Try to open it with just O_NOFOLLOW.
     assert_errno!(
         wasi::path_open(dir_fd, 0, "symlink", 0, 0, 0, 0)
-            .expect_err("opening a symlink with NOFOLLOW should fail")
-            .raw_error(),
+            .expect_err("opening a symlink with NOFOLLOW should fail"),
         wasi::ERRNO_LOOP
     );
 
@@ -81,8 +77,7 @@ unsafe fn test_nofollow_errors(dir_fd: wasi::Fd) {
             0,
             0,
         )
-        .expect_err("opening a symlink to a file as a directory")
-        .raw_error(),
+        .expect_err("opening a symlink to a file as a directory"),
         wasi::ERRNO_NOTDIR
     );
 
diff --git a/crates/test-programs/wasi-tests/src/bin/path_filestat.rs b/crates/test-programs/wasi-tests/src/bin/path_filestat.rs
index a53d7b0d6f..2b1629e40a 100644
--- a/crates/test-programs/wasi-tests/src/bin/path_filestat.rs
+++ b/crates/test-programs/wasi-tests/src/bin/path_filestat.rs
@@ -67,8 +67,7 @@ unsafe fn test_path_filestat(dir_fd: wasi::Fd) {
                 0,
                 wasi::FDFLAGS_SYNC,
             )
-            .expect_err("FDFLAGS_SYNC not supported by platform")
-            .raw_error(),
+            .expect_err("FDFLAGS_SYNC not supported by platform"),
             wasi::ERRNO_NOTSUP
         );
     }
@@ -95,8 +94,7 @@ unsafe fn test_path_filestat(dir_fd: wasi::Fd) {
             new_mtim,
             wasi::FSTFLAGS_MTIM | wasi::FSTFLAGS_MTIM_NOW,
         )
-        .expect_err("MTIM and MTIM_NOW can't both be set")
-        .raw_error(),
+        .expect_err("MTIM and MTIM_NOW can't both be set"),
         wasi::ERRNO_INVAL
     );
 
@@ -118,8 +116,7 @@ unsafe fn test_path_filestat(dir_fd: wasi::Fd) {
             0,
             wasi::FSTFLAGS_ATIM | wasi::FSTFLAGS_ATIM_NOW,
         )
-        .expect_err("ATIM & ATIM_NOW can't both be set")
-        .raw_error(),
+        .expect_err("ATIM & ATIM_NOW can't both be set"),
         wasi::ERRNO_INVAL
     );
 
diff --git a/crates/test-programs/wasi-tests/src/bin/path_link.rs b/crates/test-programs/wasi-tests/src/bin/path_link.rs
index 5932754d94..1216c334f9 100644
--- a/crates/test-programs/wasi-tests/src/bin/path_link.rs
+++ b/crates/test-programs/wasi-tests/src/bin/path_link.rs
@@ -101,8 +101,7 @@ unsafe fn test_path_link(dir_fd: wasi::Fd) {
 
     assert_errno!(
         wasi::path_link(dir_fd, 0, "file", dir_fd, "link")
-            .expect_err("creating a link to existing path should fail")
-            .raw_error(),
+            .expect_err("creating a link to existing path should fail"),
         wasi::ERRNO_EXIST
     );
     wasi::path_unlink_file(dir_fd, "link").expect("removing a file");
@@ -110,8 +109,7 @@ unsafe fn test_path_link(dir_fd: wasi::Fd) {
     // Create a link to itself
     assert_errno!(
         wasi::path_link(dir_fd, 0, "file", dir_fd, "file")
-            .expect_err("creating a link to itself should fail")
-            .raw_error(),
+            .expect_err("creating a link to itself should fail"),
         wasi::ERRNO_EXIST
     );
 
@@ -120,8 +118,7 @@ unsafe fn test_path_link(dir_fd: wasi::Fd) {
 
     assert_errno!(
         wasi::path_link(dir_fd, 0, "file", dir_fd, "link")
-            .expect_err("creating a link where target is a directory should fail")
-            .raw_error(),
+            .expect_err("creating a link where target is a directory should fail"),
         wasi::ERRNO_EXIST
     );
     wasi::path_remove_directory(dir_fd, "link").expect("removing a dir");
@@ -132,8 +129,7 @@ unsafe fn test_path_link(dir_fd: wasi::Fd) {
 
     assert_errno!(
         wasi::path_link(dir_fd, 0, "subdir", dir_fd, "link")
-            .expect_err("creating a link to a directory should fail")
-            .raw_error(),
+            .expect_err("creating a link to a directory should fail"),
         wasi::ERRNO_PERM,
         wasi::ERRNO_ACCES
     );
@@ -143,8 +139,7 @@ unsafe fn test_path_link(dir_fd: wasi::Fd) {
     // Create a link to a file with trailing slash
     assert_errno!(
         wasi::path_link(dir_fd, 0, "file", dir_fd, "link/")
-            .expect_err("creating a link to a file with trailing slash should fail")
-            .raw_error(),
+            .expect_err("creating a link to a file with trailing slash should fail"),
         wasi::ERRNO_NOENT
     );
 
@@ -171,8 +166,7 @@ unsafe fn test_path_link(dir_fd: wasi::Fd) {
 
         assert_errno!(
             wasi::path_link(dir_fd, 0, "file", dir_fd, "symlink")
-                .expect_err("creating a link where target is a dangling symlink")
-                .raw_error(),
+                .expect_err("creating a link where target is a dangling symlink"),
             wasi::ERRNO_EXIST
         );
         wasi::path_unlink_file(dir_fd, "symlink").expect("removing a symlink");
@@ -189,8 +183,7 @@ unsafe fn test_path_link(dir_fd: wasi::Fd) {
                 dir_fd,
                 "link",
             )
-            .expect_err("calling path_link with LOOKUPFLAGS_SYMLINK_FOLLOW should fail")
-            .raw_error(),
+            .expect_err("calling path_link with LOOKUPFLAGS_SYMLINK_FOLLOW should fail"),
             wasi::ERRNO_INVAL
         );
 
diff --git a/crates/test-programs/wasi-tests/src/bin/path_open_create_existing.rs b/crates/test-programs/wasi-tests/src/bin/path_open_create_existing.rs
index 21abc0598a..5c4cca2016 100644
--- a/crates/test-programs/wasi-tests/src/bin/path_open_create_existing.rs
+++ b/crates/test-programs/wasi-tests/src/bin/path_open_create_existing.rs
@@ -13,8 +13,7 @@ unsafe fn test_path_open_create_existing(dir_fd: wasi::Fd) {
             0,
             0,
         )
-        .expect_err("trying to create a file that already exists")
-        .raw_error(),
+        .expect_err("trying to create a file that already exists"),
         wasi::ERRNO_EXIST
     );
     wasi::path_unlink_file(dir_fd, "file").expect("removing a file");
diff --git a/crates/test-programs/wasi-tests/src/bin/path_open_dirfd_not_dir.rs b/crates/test-programs/wasi-tests/src/bin/path_open_dirfd_not_dir.rs
index 7fda00334c..74a0d57d25 100644
--- a/crates/test-programs/wasi-tests/src/bin/path_open_dirfd_not_dir.rs
+++ b/crates/test-programs/wasi-tests/src/bin/path_open_dirfd_not_dir.rs
@@ -8,8 +8,7 @@ unsafe fn test_dirfd_not_dir(dir_fd: wasi::Fd) {
     // Now try to open a file underneath it as if it were a directory.
     assert_errno!(
         wasi::path_open(file_fd, 0, "foo", wasi::OFLAGS_CREAT, 0, 0, 0)
-            .expect_err("non-directory base fd should get ERRNO_NOTDIR")
-            .raw_error(),
+            .expect_err("non-directory base fd should get ERRNO_NOTDIR"),
         wasi::ERRNO_NOTDIR
     );
     wasi::fd_close(file_fd).expect("closing a file");
diff --git a/crates/test-programs/wasi-tests/src/bin/path_open_missing.rs b/crates/test-programs/wasi-tests/src/bin/path_open_missing.rs
index 8074090b8d..3f56f8d75d 100644
--- a/crates/test-programs/wasi-tests/src/bin/path_open_missing.rs
+++ b/crates/test-programs/wasi-tests/src/bin/path_open_missing.rs
@@ -7,8 +7,7 @@ unsafe fn test_path_open_missing(dir_fd: wasi::Fd) {
             dir_fd, 0, "file", 0, // not passing O_CREAT here
             0, 0, 0,
         )
-        .expect_err("trying to open a file that doesn't exist")
-        .raw_error(),
+        .expect_err("trying to open a file that doesn't exist"),
         wasi::ERRNO_NOENT
     );
 }
diff --git a/crates/test-programs/wasi-tests/src/bin/path_open_read_without_rights.rs b/crates/test-programs/wasi-tests/src/bin/path_open_read_without_rights.rs
index 0adceee9a8..5cab9a033e 100644
--- a/crates/test-programs/wasi-tests/src/bin/path_open_read_without_rights.rs
+++ b/crates/test-programs/wasi-tests/src/bin/path_open_read_without_rights.rs
@@ -27,9 +27,7 @@ unsafe fn try_read_file(dir_fd: wasi::Fd) {
     // Since we no longer have the right to fd_read, trying to read a file
     // should be an error.
     assert_errno!(
-        wasi::fd_read(fd, &[iovec])
-            .expect_err("reading bytes from file should fail")
-            .raw_error(),
+        wasi::fd_read(fd, &[iovec]).expect_err("reading bytes from file should fail"),
         wasi::ERRNO_BADF
     );
 }
diff --git a/crates/test-programs/wasi-tests/src/bin/path_rename.rs b/crates/test-programs/wasi-tests/src/bin/path_rename.rs
index 8c496d9c91..325a8a390c 100644
--- a/crates/test-programs/wasi-tests/src/bin/path_rename.rs
+++ b/crates/test-programs/wasi-tests/src/bin/path_rename.rs
@@ -12,8 +12,7 @@ unsafe fn test_path_rename(dir_fd: wasi::Fd) {
     // Check that source directory doesn't exist anymore
     assert_errno!(
         wasi::path_open(dir_fd, 0, "source", wasi::OFLAGS_DIRECTORY, 0, 0, 0)
-            .expect_err("opening a nonexistent path as a directory should fail")
-            .raw_error(),
+            .expect_err("opening a nonexistent path as a directory should fail"),
         wasi::ERRNO_NOENT
     );
 
@@ -41,8 +40,7 @@ unsafe fn test_path_rename(dir_fd: wasi::Fd) {
         // Check that source directory doesn't exist anymore
         assert_errno!(
             wasi::path_open(dir_fd, 0, "source", wasi::OFLAGS_DIRECTORY, 0, 0, 0)
-                .expect_err("opening a nonexistent path as a directory")
-                .raw_error(),
+                .expect_err("opening a nonexistent path as a directory"),
             wasi::ERRNO_NOENT
         );
 
@@ -72,8 +70,7 @@ unsafe fn test_path_rename(dir_fd: wasi::Fd) {
 
     assert_errno!(
         wasi::path_rename(dir_fd, "source", dir_fd, "target")
-            .expect_err("renaming directory to a nonempty directory")
-            .raw_error(),
+            .expect_err("renaming directory to a nonempty directory"),
         windows => wasi::ERRNO_ACCES,
         unix => wasi::ERRNO_NOTEMPTY
     );
@@ -85,8 +82,7 @@ unsafe fn test_path_rename(dir_fd: wasi::Fd) {
         // Try renaming dir to a file
         assert_errno!(
             wasi::path_rename(dir_fd, "source", dir_fd, "target/file")
-                .expect_err("renaming a directory to a file")
-                .raw_error(),
+                .expect_err("renaming a directory to a file"),
             wasi::ERRNO_NOTDIR
         );
         wasi::path_unlink_file(dir_fd, "target/file").expect("removing a file");
@@ -107,8 +103,7 @@ unsafe fn test_path_rename(dir_fd: wasi::Fd) {
     // Check that source file doesn't exist anymore
     assert_errno!(
         wasi::path_open(dir_fd, 0, "source", 0, 0, 0, 0)
-            .expect_err("opening a nonexistent path should fail")
-            .raw_error(),
+            .expect_err("opening a nonexistent path should fail"),
         wasi::ERRNO_NOENT
     );
 
@@ -131,9 +126,7 @@ unsafe fn test_path_rename(dir_fd: wasi::Fd) {
 
     // Check that source file doesn't exist anymore
     assert_errno!(
-        wasi::path_open(dir_fd, 0, "source", 0, 0, 0, 0)
-            .expect_err("opening a nonexistent path")
-            .raw_error(),
+        wasi::path_open(dir_fd, 0, "source", 0, 0, 0, 0).expect_err("opening a nonexistent path"),
         wasi::ERRNO_NOENT
     );
 
@@ -153,8 +146,7 @@ unsafe fn test_path_rename(dir_fd: wasi::Fd) {
 
     assert_errno!(
         wasi::path_rename(dir_fd, "source", dir_fd, "target")
-            .expect_err("renaming a file to existing directory should fail")
-            .raw_error(),
+            .expect_err("renaming a file to existing directory should fail"),
         windows => wasi::ERRNO_ACCES,
         unix => wasi::ERRNO_ISDIR
     );
diff --git a/crates/test-programs/wasi-tests/src/bin/path_rename_file_trailing_slashes.rs b/crates/test-programs/wasi-tests/src/bin/path_rename_file_trailing_slashes.rs
index b884a84d03..853b1d4071 100644
--- a/crates/test-programs/wasi-tests/src/bin/path_rename_file_trailing_slashes.rs
+++ b/crates/test-programs/wasi-tests/src/bin/path_rename_file_trailing_slashes.rs
@@ -11,20 +11,19 @@ unsafe fn test_path_rename_trailing_slashes(dir_fd: wasi::Fd) {
 
     assert_errno!(
         wasi::path_rename(dir_fd, "source/", dir_fd, "target")
-            .expect_err("renaming a file with a trailing slash in the source name should fail")
-            .raw_error(),
+            .expect_err("renaming a file with a trailing slash in the source name should fail"),
         wasi::ERRNO_NOTDIR
     );
     assert_errno!(
-        wasi::path_rename(dir_fd, "source", dir_fd, "target/")
-            .expect_err("renaming a file with a trailing slash in the destination name should fail")
-            .raw_error(),
+        wasi::path_rename(dir_fd, "source", dir_fd, "target/").expect_err(
+            "renaming a file with a trailing slash in the destination name should fail"
+        ),
         wasi::ERRNO_NOTDIR
     );
     assert_errno!(
-        wasi::path_rename(dir_fd, "source/", dir_fd, "target/")
-            .expect_err("renaming a file with a trailing slash in the source and destination names should fail")
-            .raw_error(),
+        wasi::path_rename(dir_fd, "source/", dir_fd, "target/").expect_err(
+            "renaming a file with a trailing slash in the source and destination names should fail"
+        ),
         wasi::ERRNO_NOTDIR
     );
     wasi::path_unlink_file(dir_fd, "source").expect("removing a file");
diff --git a/crates/test-programs/wasi-tests/src/bin/path_symlink_trailing_slashes.rs b/crates/test-programs/wasi-tests/src/bin/path_symlink_trailing_slashes.rs
index f814303d75..f27ced633e 100644
--- a/crates/test-programs/wasi-tests/src/bin/path_symlink_trailing_slashes.rs
+++ b/crates/test-programs/wasi-tests/src/bin/path_symlink_trailing_slashes.rs
@@ -6,8 +6,7 @@ unsafe fn test_path_symlink_trailing_slashes(dir_fd: wasi::Fd) {
         // Dangling symlink: Link destination shouldn't end with a slash.
         assert_errno!(
             wasi::path_symlink("source", dir_fd, "target/")
-                .expect_err("link destination ending with a slash should fail")
-                .raw_error(),
+                .expect_err("link destination ending with a slash should fail"),
             wasi::ERRNO_NOENT
         );
 
@@ -21,8 +20,7 @@ unsafe fn test_path_symlink_trailing_slashes(dir_fd: wasi::Fd) {
     wasi::path_create_directory(dir_fd, "target").expect("creating a directory");
     assert_errno!(
         wasi::path_symlink("source", dir_fd, "target/")
-            .expect_err("link destination already exists")
-            .raw_error(),
+            .expect_err("link destination already exists"),
         unix => wasi::ERRNO_EXIST,
         windows => wasi::ERRNO_NOENT
     );
@@ -32,8 +30,7 @@ unsafe fn test_path_symlink_trailing_slashes(dir_fd: wasi::Fd) {
     wasi::path_create_directory(dir_fd, "target").expect("creating a directory");
     assert_errno!(
         wasi::path_symlink("source", dir_fd, "target")
-            .expect_err("link destination already exists")
-            .raw_error(),
+            .expect_err("link destination already exists"),
         unix => wasi::ERRNO_EXIST,
         windows => wasi::ERRNO_NOENT
     );
@@ -44,8 +41,7 @@ unsafe fn test_path_symlink_trailing_slashes(dir_fd: wasi::Fd) {
 
     assert_errno!(
         wasi::path_symlink("source", dir_fd, "target/")
-            .expect_err("link destination already exists")
-            .raw_error(),
+            .expect_err("link destination already exists"),
         unix => wasi::ERRNO_NOTDIR,
         windows => wasi::ERRNO_NOENT
     );
@@ -56,8 +52,7 @@ unsafe fn test_path_symlink_trailing_slashes(dir_fd: wasi::Fd) {
 
     assert_errno!(
         wasi::path_symlink("source", dir_fd, "target")
-            .expect_err("link destination already exists")
-            .raw_error(),
+            .expect_err("link destination already exists"),
         unix => wasi::ERRNO_EXIST,
         windows => wasi::ERRNO_NOENT
     );
diff --git a/crates/test-programs/wasi-tests/src/bin/poll_oneoff_files.rs b/crates/test-programs/wasi-tests/src/bin/poll_oneoff_files.rs
index f84c7ec4af..cbf9803130 100644
--- a/crates/test-programs/wasi-tests/src/bin/poll_oneoff_files.rs
+++ b/crates/test-programs/wasi-tests/src/bin/poll_oneoff_files.rs
@@ -3,7 +3,7 @@ use wasi_tests::{assert_errno, open_scratch_directory};
 
 const CLOCK_ID: wasi::Userdata = 0x0123_45678;
 
-unsafe fn poll_oneoff_impl(r#in: &[wasi::Subscription]) -> Result<Vec<wasi::Event>, wasi::Error> {
+unsafe fn poll_oneoff_impl(r#in: &[wasi::Subscription]) -> Result<Vec<wasi::Event>, wasi::Errno> {
     let mut out: Vec<wasi::Event> = Vec::new();
     out.resize_with(r#in.len(), || {
         MaybeUninit::<wasi::Event>::zeroed().assume_init()
@@ -17,7 +17,7 @@ unsafe fn poll_oneoff_impl(r#in: &[wasi::Subscription]) -> Result<Vec<wasi::Even
 /// seen their events occur.
 unsafe fn poll_oneoff_with_retry(
     r#in: &[wasi::Subscription],
-) -> Result<Vec<wasi::Event>, wasi::Error> {
+) -> Result<Vec<wasi::Event>, wasi::Errno> {
     let mut subscriptions = r#in.to_vec();
     let mut events = Vec::new();
     while !subscriptions.is_empty() {
@@ -47,8 +47,7 @@ unsafe fn test_empty_poll() {
     let mut out: Vec<wasi::Event> = Vec::new();
     assert_errno!(
         wasi::poll_oneoff(r#in.as_ptr(), out.as_mut_ptr(), r#in.len())
-            .expect_err("empty poll_oneoff should fail")
-            .raw_error(),
+            .expect_err("empty poll_oneoff should fail"),
         wasi::ERRNO_INVAL
     );
 }
@@ -64,7 +63,7 @@ unsafe fn test_timeout() {
     let r#in = [wasi::Subscription {
         userdata: CLOCK_ID,
         u: wasi::SubscriptionU {
-            tag: wasi::EVENTTYPE_CLOCK,
+            tag: wasi::EVENTTYPE_CLOCK.raw(),
             u: wasi::SubscriptionUU { clock },
         },
     }];
@@ -75,7 +74,7 @@ unsafe fn test_timeout() {
     let event = &out[0];
     assert_errno!(event.error, wasi::ERRNO_SUCCESS);
     assert_eq!(
-        event.r#type,
+        event.type_,
         wasi::EVENTTYPE_CLOCK,
         "the event.type should equal clock"
     );
@@ -102,7 +101,7 @@ unsafe fn test_sleep() {
     let r#in = [wasi::Subscription {
         userdata: CLOCK_ID,
         u: wasi::SubscriptionU {
-            tag: wasi::EVENTTYPE_CLOCK,
+            tag: wasi::EVENTTYPE_CLOCK.raw(),
             u: wasi::SubscriptionUU { clock },
         },
     }];
@@ -113,7 +112,7 @@ unsafe fn test_sleep() {
     let event = &out[0];
     assert_errno!(event.error, wasi::ERRNO_SUCCESS);
     assert_eq!(
-        event.r#type,
+        event.type_,
         wasi::EVENTTYPE_CLOCK,
         "the event.type should equal clock"
     );
@@ -132,7 +131,7 @@ unsafe fn test_fd_readwrite(readable_fd: wasi::Fd, writable_fd: wasi::Fd, error_
         wasi::Subscription {
             userdata: 1,
             u: wasi::SubscriptionU {
-                tag: wasi::EVENTTYPE_FD_READ,
+                tag: wasi::EVENTTYPE_FD_READ.raw(),
                 u: wasi::SubscriptionUU {
                     fd_read: wasi::SubscriptionFdReadwrite {
                         file_descriptor: readable_fd,
@@ -143,7 +142,7 @@ unsafe fn test_fd_readwrite(readable_fd: wasi::Fd, writable_fd: wasi::Fd, error_
         wasi::Subscription {
             userdata: 2,
             u: wasi::SubscriptionU {
-                tag: wasi::EVENTTYPE_FD_WRITE,
+                tag: wasi::EVENTTYPE_FD_WRITE.raw(),
                 u: wasi::SubscriptionUU {
                     fd_write: wasi::SubscriptionFdReadwrite {
                         file_descriptor: writable_fd,
@@ -160,7 +159,7 @@ unsafe fn test_fd_readwrite(readable_fd: wasi::Fd, writable_fd: wasi::Fd, error_
     );
     assert_errno!(out[0].error, error_code);
     assert_eq!(
-        out[0].r#type,
+        out[0].type_,
         wasi::EVENTTYPE_FD_READ,
         "the event.type_ should equal FD_READ"
     );
@@ -170,7 +169,7 @@ unsafe fn test_fd_readwrite(readable_fd: wasi::Fd, writable_fd: wasi::Fd, error_
     );
     assert_errno!(out[1].error, error_code);
     assert_eq!(
-        out[1].r#type,
+        out[1].type_,
         wasi::EVENTTYPE_FD_WRITE,
         "the event.type_ should equal FD_WRITE"
     );
@@ -244,7 +243,7 @@ unsafe fn test_fd_readwrite_invalid_fd() {
         wasi::Subscription {
             userdata: 1,
             u: wasi::SubscriptionU {
-                tag: wasi::EVENTTYPE_FD_READ,
+                tag: wasi::EVENTTYPE_FD_READ.raw(),
                 u: wasi::SubscriptionUU {
                     fd_read: fd_readwrite,
                 },
@@ -253,7 +252,7 @@ unsafe fn test_fd_readwrite_invalid_fd() {
         wasi::Subscription {
             userdata: 2,
             u: wasi::SubscriptionU {
-                tag: wasi::EVENTTYPE_FD_WRITE,
+                tag: wasi::EVENTTYPE_FD_WRITE.raw(),
                 u: wasi::SubscriptionUU {
                     fd_write: fd_readwrite,
                 },
@@ -261,7 +260,7 @@ unsafe fn test_fd_readwrite_invalid_fd() {
         },
     ];
     let err = poll_oneoff_impl(&r#in).unwrap_err();
-    assert_eq!(err.raw_error(), wasi::ERRNO_BADF)
+    assert_eq!(err, wasi::ERRNO_BADF)
 }
 
 unsafe fn test_poll_oneoff(dir_fd: wasi::Fd) {
diff --git a/crates/test-programs/wasi-tests/src/bin/poll_oneoff_stdio.rs b/crates/test-programs/wasi-tests/src/bin/poll_oneoff_stdio.rs
index 8b2929b273..d3b39c95aa 100644
--- a/crates/test-programs/wasi-tests/src/bin/poll_oneoff_stdio.rs
+++ b/crates/test-programs/wasi-tests/src/bin/poll_oneoff_stdio.rs
@@ -6,7 +6,7 @@ const TIMEOUT: u64 = 200_000_000u64; // 200 milliseconds, required to satisfy sl
 const CLOCK_ID: wasi::Userdata = 0x0123_45678;
 const STDIN_ID: wasi::Userdata = 0x8765_43210;
 
-unsafe fn poll_oneoff_impl(r#in: &[wasi::Subscription]) -> Result<Vec<wasi::Event>, wasi::Error> {
+unsafe fn poll_oneoff_impl(r#in: &[wasi::Subscription]) -> Result<Vec<wasi::Event>, wasi::Errno> {
     let mut out: Vec<wasi::Event> = Vec::new();
     out.resize_with(r#in.len(), || {
         MaybeUninit::<wasi::Event>::zeroed().assume_init()
@@ -31,14 +31,14 @@ unsafe fn test_stdin_read() {
         wasi::Subscription {
             userdata: CLOCK_ID,
             u: wasi::SubscriptionU {
-                tag: wasi::EVENTTYPE_CLOCK,
+                tag: wasi::EVENTTYPE_CLOCK.raw(),
                 u: wasi::SubscriptionUU { clock },
             },
         },
         wasi::Subscription {
             userdata: STDIN_ID,
             u: wasi::SubscriptionU {
-                tag: wasi::EVENTTYPE_FD_READ,
+                tag: wasi::EVENTTYPE_FD_READ.raw(),
                 u: wasi::SubscriptionUU {
                     fd_read: fd_readwrite,
                 },
@@ -50,20 +50,20 @@ unsafe fn test_stdin_read() {
     // Both are valid behaviors that depend on the test environment.
     assert!(out.len() >= 1, "stdin read should return at least 1 event");
     for event in out {
-        if event.r#type == wasi::EVENTTYPE_CLOCK {
+        if event.type_ == wasi::EVENTTYPE_CLOCK {
             assert_errno!(event.error, wasi::ERRNO_SUCCESS);
             assert_eq!(
                 event.userdata, CLOCK_ID,
                 "the event.userdata should contain CLOCK_ID",
             );
-        } else if event.r#type == wasi::EVENTTYPE_FD_READ {
+        } else if event.type_ == wasi::EVENTTYPE_FD_READ {
             assert_errno!(event.error, wasi::ERRNO_SUCCESS);
             assert_eq!(
                 event.userdata, STDIN_ID,
                 "the event.userdata should contain STDIN_ID",
             );
         } else {
-            panic!("unexpected event type {}", event.r#type);
+            panic!("unexpected event type {}", event.type_.raw());
         }
     }
 }
@@ -74,7 +74,7 @@ fn writable_subs(h: &HashMap<u64, wasi::Fd>) -> Vec<wasi::Subscription> {
         .map(|(ud, fd)| wasi::Subscription {
             userdata: *ud,
             u: wasi::SubscriptionU {
-                tag: wasi::EVENTTYPE_FD_WRITE,
+                tag: wasi::EVENTTYPE_FD_WRITE.raw(),
                 u: wasi::SubscriptionUU {
                     fd_write: wasi::SubscriptionFdReadwrite {
                         file_descriptor: *fd,
@@ -92,7 +92,7 @@ unsafe fn test_stdout_stderr_write() {
     let clock = wasi::Subscription {
         userdata: CLOCK_ID,
         u: wasi::SubscriptionU {
-            tag: wasi::EVENTTYPE_CLOCK,
+            tag: wasi::EVENTTYPE_CLOCK.raw(),
             u: wasi::SubscriptionUU {
                 clock: wasi::SubscriptionClock {
                     id: wasi::CLOCKID_MONOTONIC,
@@ -114,7 +114,7 @@ unsafe fn test_stdout_stderr_write() {
                 }
                 ud => {
                     if let Some(_) = writable.remove(&ud) {
-                        assert_eq!(event.r#type, wasi::EVENTTYPE_FD_WRITE);
+                        assert_eq!(event.type_, wasi::EVENTTYPE_FD_WRITE);
                         assert_errno!(event.error, wasi::ERRNO_SUCCESS);
                     } else {
                         panic!("Unknown userdata {}, pending sub: {:?}", ud, writable)
diff --git a/crates/test-programs/wasi-tests/src/bin/readlink.rs b/crates/test-programs/wasi-tests/src/bin/readlink.rs
index 81fa33188d..b06c01c593 100644
--- a/crates/test-programs/wasi-tests/src/bin/readlink.rs
+++ b/crates/test-programs/wasi-tests/src/bin/readlink.rs
@@ -25,7 +25,7 @@ unsafe fn test_readlink(dir_fd: wasi::Fd) {
     let err = wasi::path_readlink(dir_fd, "symlink", buf.as_mut_ptr(), buf.len())
         .err()
         .expect("readlink with too-small buffer should fail");
-    assert_errno!(err.raw_error(), wasi::ERRNO_RANGE);
+    assert_errno!(err, wasi::ERRNO_RANGE);
 
     // Clean up.
     wasi::path_unlink_file(dir_fd, "target").expect("removing a file");
diff --git a/crates/test-programs/wasi-tests/src/bin/remove_directory_trailing_slashes.rs b/crates/test-programs/wasi-tests/src/bin/remove_directory_trailing_slashes.rs
index e3805a96ec..9628c7ad5c 100644
--- a/crates/test-programs/wasi-tests/src/bin/remove_directory_trailing_slashes.rs
+++ b/crates/test-programs/wasi-tests/src/bin/remove_directory_trailing_slashes.rs
@@ -21,16 +21,14 @@ unsafe fn test_remove_directory_trailing_slashes(dir_fd: wasi::Fd) {
     // Test that removing it with no trailing slash fails.
     assert_errno!(
         wasi::path_remove_directory(dir_fd, "file")
-            .expect_err("remove_directory without a trailing slash on a file should fail")
-            .raw_error(),
+            .expect_err("remove_directory without a trailing slash on a file should fail"),
         wasi::ERRNO_NOTDIR
     );
 
     // Test that removing it with a trailing slash fails.
     assert_errno!(
         wasi::path_remove_directory(dir_fd, "file/")
-            .expect_err("remove_directory with a trailing slash on a file should fail")
-            .raw_error(),
+            .expect_err("remove_directory with a trailing slash on a file should fail"),
         unix => wasi::ERRNO_NOTDIR,
         windows => wasi::ERRNO_NOENT
     );
diff --git a/crates/test-programs/wasi-tests/src/bin/remove_nonempty_directory.rs b/crates/test-programs/wasi-tests/src/bin/remove_nonempty_directory.rs
index 19488e748d..6732ba537e 100644
--- a/crates/test-programs/wasi-tests/src/bin/remove_nonempty_directory.rs
+++ b/crates/test-programs/wasi-tests/src/bin/remove_nonempty_directory.rs
@@ -11,8 +11,7 @@ unsafe fn test_remove_nonempty_directory(dir_fd: wasi::Fd) {
     // Test that attempting to unlink the first directory returns the expected error code.
     assert_errno!(
         wasi::path_remove_directory(dir_fd, "dir")
-            .expect_err("remove_directory on a directory should return ENOTEMPTY")
-            .raw_error(),
+            .expect_err("remove_directory on a directory should return ENOTEMPTY"),
         wasi::ERRNO_NOTEMPTY
     );
 
diff --git a/crates/test-programs/wasi-tests/src/bin/renumber.rs b/crates/test-programs/wasi-tests/src/bin/renumber.rs
index 7867a54017..1a50f02ade 100644
--- a/crates/test-programs/wasi-tests/src/bin/renumber.rs
+++ b/crates/test-programs/wasi-tests/src/bin/renumber.rs
@@ -47,9 +47,7 @@ unsafe fn test_renumber(dir_fd: wasi::Fd) {
 
     // Ensure that fd_from is closed
     assert_errno!(
-        wasi::fd_close(fd_from)
-            .expect_err("closing already closed file descriptor")
-            .raw_error(),
+        wasi::fd_close(fd_from).expect_err("closing already closed file descriptor"),
         wasi::ERRNO_BADF
     );
 
diff --git a/crates/test-programs/wasi-tests/src/bin/symlink_loop.rs b/crates/test-programs/wasi-tests/src/bin/symlink_loop.rs
index c14356f897..1c3226adb7 100644
--- a/crates/test-programs/wasi-tests/src/bin/symlink_loop.rs
+++ b/crates/test-programs/wasi-tests/src/bin/symlink_loop.rs
@@ -9,8 +9,7 @@ unsafe fn test_symlink_loop(dir_fd: wasi::Fd) {
         // Try to open it.
         assert_errno!(
             wasi::path_open(dir_fd, 0, "symlink", 0, 0, 0, 0)
-                .expect_err("opening a self-referencing symlink")
-                .raw_error(),
+                .expect_err("opening a self-referencing symlink"),
             wasi::ERRNO_LOOP
         );
 
diff --git a/crates/test-programs/wasi-tests/src/bin/truncation_rights.rs b/crates/test-programs/wasi-tests/src/bin/truncation_rights.rs
index 5faa85fd91..0480d74b98 100644
--- a/crates/test-programs/wasi-tests/src/bin/truncation_rights.rs
+++ b/crates/test-programs/wasi-tests/src/bin/truncation_rights.rs
@@ -66,8 +66,7 @@ unsafe fn test_truncation_rights(dir_fd: wasi::Fd) {
         // wasi_unstable::RIGHT_PATH_FILESTAT_SET_SIZE right.
         assert_errno!(
             wasi::path_open(dir_fd, 0, "file", wasi::OFLAGS_TRUNC, 0, 0, 0)
-                .expect_err("truncating a file without path_filestat_set_size right")
-                .raw_error(),
+                .expect_err("truncating a file without path_filestat_set_size right"),
             wasi::ERRNO_PERM
         );
     }
diff --git a/crates/test-programs/wasi-tests/src/bin/unlink_file_trailing_slashes.rs b/crates/test-programs/wasi-tests/src/bin/unlink_file_trailing_slashes.rs
index 519ef230f6..bedecd9aad 100644
--- a/crates/test-programs/wasi-tests/src/bin/unlink_file_trailing_slashes.rs
+++ b/crates/test-programs/wasi-tests/src/bin/unlink_file_trailing_slashes.rs
@@ -8,8 +8,7 @@ unsafe fn test_unlink_file_trailing_slashes(dir_fd: wasi::Fd) {
     // Test that unlinking it fails.
     assert_errno!(
         wasi::path_unlink_file(dir_fd, "dir")
-            .expect_err("unlink_file on a directory should fail")
-            .raw_error(),
+            .expect_err("unlink_file on a directory should fail"),
         macos => wasi::ERRNO_PERM,
         unix => wasi::ERRNO_ISDIR,
         windows => wasi::ERRNO_ACCES
@@ -18,8 +17,7 @@ unsafe fn test_unlink_file_trailing_slashes(dir_fd: wasi::Fd) {
     // Test that unlinking it with a trailing flash fails.
     assert_errno!(
         wasi::path_unlink_file(dir_fd, "dir/")
-            .expect_err("unlink_file on a directory should fail")
-            .raw_error(),
+            .expect_err("unlink_file on a directory should fail"),
         macos => wasi::ERRNO_PERM,
         unix => wasi::ERRNO_ISDIR,
         windows => wasi::ERRNO_ACCES
@@ -34,8 +32,7 @@ unsafe fn test_unlink_file_trailing_slashes(dir_fd: wasi::Fd) {
     // Test that unlinking it with a trailing flash fails.
     assert_errno!(
         wasi::path_unlink_file(dir_fd, "file/")
-            .expect_err("unlink_file with a trailing slash should fail")
-            .raw_error(),
+            .expect_err("unlink_file with a trailing slash should fail"),
         unix => wasi::ERRNO_NOTDIR,
         windows => wasi::ERRNO_NOENT
     );
diff --git a/crates/test-programs/wasi-tests/src/lib.rs b/crates/test-programs/wasi-tests/src/lib.rs
index bddd7c3caf..da6faf00e0 100644
--- a/crates/test-programs/wasi-tests/src/lib.rs
+++ b/crates/test-programs/wasi-tests/src/lib.rs
@@ -18,7 +18,7 @@ pub fn open_scratch_directory(path: &str) -> Result<wasi::Fd, String> {
                 Ok(s) => s,
                 Err(_) => break,
             };
-            if stat.tag != wasi::PREOPENTYPE_DIR {
+            if stat.tag != wasi::PREOPENTYPE_DIR.raw() {
                 continue;
             }
             let mut dst = Vec::with_capacity(stat.u.dir.pr_name_len);
@@ -122,8 +122,8 @@ macro_rules! assert_errno {
             }
             assert!( $( e == $i || )+ false,
                 "expected errno {}; got {}",
-                Alt(&[ $( wasi::errno_name($i) ),+ ]),
-                wasi::errno_name(e),
+                Alt(&[ $( $i.name() ),+ ]),
+                e.name()
             )
         }
     };