diff --git a/.vscode/settings.json b/.vscode/settings.json
index 90e722fc0c..fd702539a8 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,7 +1,7 @@
 {
     "editor.formatOnSave": true,
     "rust-client.disableRustup": false,
-    "rust.target": "x86_64-pc-windows-gnu",
+    // "rust.target": "x86_64-pc-windows-gnu",
     //"rust.sysroot": "/home/marcin/.rustup/toolchains/stable-x86_64-pc-windows-gnu/",
     "rust.all_targets": false
 }
\ No newline at end of file
diff --git a/src/error.rs b/src/error.rs
index 5fc82db323..ffe79b6aa2 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -134,11 +134,18 @@ impl Error {
     pub(crate) fn as_wasi_errno(&self) -> host::__wasi_errno_t {
         match self {
             Self::Wasi(no) => no.as_raw_errno(),
+            Self::Io(e) => errno_from_ioerror(e.to_owned()),
             #[cfg(unix)]
-            Self::Nix(err) => {
-                crate::sys::host_impl::errno_from_nix(err.as_errno().unwrap()).as_wasi_errno()
-            } // FIXME unwrap
-            Self::Io(e) => errno_from_ioerror(e.to_owned()), // fixme clone
+            Self::Nix(err) => err
+                .as_errno()
+                .map_or_else(
+                    || {
+                        log::debug!("Unknown nix errno: {}", err);
+                        Self::ENOSYS
+                    },
+                    crate::sys::host_impl::errno_from_nix,
+                )
+                .as_wasi_errno(),
             #[cfg(windows)]
             Self::Win(err) => crate::sys::host_impl::errno_from_win(*err),
         }
diff --git a/src/sys/unix/host_impl.rs b/src/sys/unix/host_impl.rs
index 468d98c3d0..be11942c00 100644
--- a/src/sys/unix/host_impl.rs
+++ b/src/sys/unix/host_impl.rs
@@ -178,8 +178,6 @@ pub(crate) fn filetype_from_nix(sflags: nix::sys::stat::SFlag) -> host::__wasi_f
 pub(crate) fn filestat_from_nix(
     filestat: nix::sys::stat::FileStat,
 ) -> Result<host::__wasi_filestat_t> {
-    use std::convert::TryFrom;
-
     fn filestat_to_timestamp(secs: u64, nsecs: u64) -> Result<host::__wasi_timestamp_t> {
         secs.checked_mul(1_000_000_000)
             .and_then(|sec_nsec| sec_nsec.checked_add(nsecs))
@@ -187,8 +185,8 @@ pub(crate) fn filestat_from_nix(
     }
 
     let filetype = nix::sys::stat::SFlag::from_bits_truncate(filestat.st_mode);
-    let dev = host::__wasi_device_t::try_from(filestat.st_dev)?;
-    let ino = host::__wasi_inode_t::try_from(filestat.st_ino)?;
+    let dev = host::__wasi_device_t::from(filestat.st_dev);
+    let ino = host::__wasi_inode_t::from(filestat.st_ino);
     let st_atim = filestat_to_timestamp(filestat.st_atime as u64, filestat.st_atime_nsec as u64)?;
     let st_ctim = filestat_to_timestamp(filestat.st_ctime as u64, filestat.st_ctime_nsec as u64)?;
     let st_mtim = filestat_to_timestamp(filestat.st_mtime as u64, filestat.st_mtime_nsec as u64)?;
diff --git a/src/sys/unix/hostcalls_impl/fs.rs b/src/sys/unix/hostcalls_impl/fs.rs
index 04dde6277b..bbdc3f5f82 100644
--- a/src/sys/unix/hostcalls_impl/fs.rs
+++ b/src/sys/unix/hostcalls_impl/fs.rs
@@ -442,8 +442,7 @@ pub(crate) fn path_filestat_set_times(
     };
 
     let fd = resolved.dirfd().as_raw_fd().into();
-    utimensat(fd, resolved.path(), &atim, &mtim, atflags)
-        .map_err(|e| host_impl::errno_from_nix(e.as_errno().unwrap()))
+    utimensat(fd, resolved.path(), &atim, &mtim, atflags).map_err(Into::into)
 }
 
 pub(crate) fn path_symlink(old_path: &str, resolved: PathGet) -> Result<()> {
diff --git a/src/sys/unix/hostcalls_impl/fs_helpers.rs b/src/sys/unix/hostcalls_impl/fs_helpers.rs
index 435da35f77..31cd355ba5 100644
--- a/src/sys/unix/hostcalls_impl/fs_helpers.rs
+++ b/src/sys/unix/hostcalls_impl/fs_helpers.rs
@@ -50,7 +50,7 @@ pub(crate) fn openat(dirfd: &File, path: &str) -> Result<File> {
         Mode::empty(),
     )
     .map(|new_fd| unsafe { File::from_raw_fd(new_fd) })
-    .map_err(|e| host_impl::errno_from_nix(e.as_errno().unwrap()))
+    .map_err(Into::into)
 }
 
 pub(crate) fn readlinkat(dirfd: &File, path: &str) -> Result<String> {
@@ -60,7 +60,7 @@ pub(crate) fn readlinkat(dirfd: &File, path: &str) -> Result<String> {
     let readlink_buf = &mut [0u8; libc::PATH_MAX as usize + 1];
 
     fcntl::readlinkat(dirfd.as_raw_fd(), path, readlink_buf)
-        .map_err(|e| host_impl::errno_from_nix(e.as_errno().unwrap()))
+        .map_err(Into::into)
         .and_then(host_impl::path_from_host)
 }