Fix failing system tests on Cygwin

The main changes are: - disabling some checks related to POSIX file permissions when a filesystem is mounted with "noacl" (default on MSYS2) - disabling some checks related to symlinks when using fake ones (file copy) Windows with acl hasn't been tested because 1) Cygwin itself does not have any Rust package yet to compile fish, and 2) MSYS2 defaults to `noacl` Part of #12171
2026-04-19 06:31:13 -03:00 · 2025-11-17 12:25:40 -08:00
parent 52495c8124
commit 440e7fcbc1
27 changed files with 478 additions and 117 deletions
--- a/build_tools/check.sh
+++ b/build_tools/check.sh
@@ -8,11 +8,29 @@ if [ "$FISH_CHECK_LINT" = false ]; then
    lint=false
 fi

+case "$(uname)" in
+    MSYS*)
+        is_cygwin=true
+        cygwin_var=MSYS
+        ;;
+    CYGWIN*)
+        is_cygwin=true
+        cygwin_var=CYGWIN
+        ;;
+    *)
+        is_cygwin=false
+        ;;
+esac
+
 check_dependency_versions=false
 if [ "${FISH_CHECK_DEPENDENCY_VERSIONS:-false}" != false ]; then
    check_dependency_versions=true
 fi

+green='\e[0;32m'
+yellow='\e[1;33m'
+reset='\e[m'
+
 if $check_dependency_versions; then
    command -v curl
    command -v jq
@@ -83,12 +101,45 @@ if $lint; then
        cargo clippy --workspace --all-targets $features
    done
 fi
-cargo test --no-default-features --workspace --all-targets
+
+# When running `cargo test`, some binaries (e.g. `fish_gettext_extraction`)
+# are dynamically linked against Rust's `std-xxx.dll` instead of being
+# statically link as they usually are.
+# On Cygwin, `PATH`is not properly updated to point to the `std-xxx.dll`
+# location, so we have to do it manually.
+# See:
+# - https://github.com/rust-lang/rust/issues/149050
+# - https://github.com/msys2/MSYS2-packages/issues/5784
+(
+    if $is_cygwin; then
+        export PATH="$PATH:$(rustc --print target-libdir)"
+    fi
+    cargo test --no-default-features --workspace --all-targets
+)
 cargo test --doc --workspace
+
 if $lint; then
    cargo doc --workspace --no-deps
 fi
-FISH_GETTEXT_EXTRACTION_DIR=$gettext_template_dir "$workspace_root/tests/test_driver.py" "$build_dir"
+
+# Using "()" not "{}" because we do want a subshell (for the export)
+system_tests() (
+    [ -n "$@" ] && export "$@"
+    export FISH_GETTEXT_EXTRACTION_DIR="$gettext_template_dir"
+    "$workspace_root/tests/test_driver.py" "$build_dir"
+)
+
+test_cmd='FISH_GETTEXT_EXTRACTION_DIR="$gettext_template_dir" "$workspace_root/tests/test_driver.py" "$build_dir"'
+if $is_cygwin; then
+    echo -e "=== Running ${green}integration tests ${yellow}with${green} symlinks${reset}"
+    system_tests $cygwin_var=winsymlinks
+
+    echo -e "=== Running ${green}integration tests ${yellow}without${green} symlinks${reset}"
+    system_tests $cygwin_var=winsymlinks
+else
+    echo -e "=== Running ${green}integration tests${reset}"
+    system_tests
+fi

 exit
 }
--- a/share/functions/__fish_cygwin_noacl.fish
+++ b/share/functions/__fish_cygwin_noacl.fish
@@ -0,0 +1,10 @@
+# localization: skip(private)
+function __fish_cygwin_noacl
+    # MSYS (default) and Cygwin (non-default) mounts may not support POSIX permissions.
+    __fish_is_cygwin
+    and {
+        mount |
+            string match "*on $(stat -c %m -- $argv[1]) *" |
+            string match -qr "[(,]noacl[),]"
+    }
+end
--- a/share/functions/__fish_is_cygwin.fish
+++ b/share/functions/__fish_is_cygwin.fish
@@ -0,0 +1,4 @@
+# localization: skip(private)
+function __fish_is_cygwin
+    __fish_uname | string match -qr "^(MSYS|CYGWIN)"
+end
--- a/share/functions/__fish_make_cache_dir.fish
+++ b/share/functions/__fish_make_cache_dir.fish
@@ -9,6 +9,21 @@ function __fish_make_cache_dir --description "Create and return XDG_CACHE_HOME"
    # So if you call `__fish_make_cache_dir completions`,
    # this creates e.g. ~/.cache/fish/completions
    if not path is -d $xdg_cache_home/fish/"$argv[1]"
-        mkdir -m 700 -p $xdg_cache_home/fish/"$argv[1]"
+        set -l mkdir_options -m 700
+
+        # Can't set the permission in Cygwin on a `noacl` mount
+        if __fish_is_cygwin
+            # Find the first existing parent so we can `stat` it and get its mountpoint
+            set -l existing_parent $xdg_cache_home/fish/"$argv[1]"
+            while not path is -d $existing_parent
+                set existing_parent (path dirname $existing_parent)
+            end
+
+            if __fish_cygwin_noacl "$existing_parent"
+                set mkdir_options
+            end
+        end
+
+        mkdir $mkdir_options -p $xdg_cache_home/fish/"$argv[1]"
    end; and echo $xdg_cache_home/fish/"$argv[1]"
 end
--- a/tests/checks/cd.fish
+++ b/tests/checks/cd.fish
@@ -2,6 +2,8 @@

 set -g fish (realpath $fish)

+cygwin_nosymlinks && set nosymlinks
+
 # Store pwd to later go back before cleaning up
 set -l oldpwd (pwd)

@@ -25,30 +27,37 @@ rm -rf $tmp
 # Create a test directory to store our stuff.
 # macOS likes to return symlinks from (mktemp -d), make sure it does not.
 set -l base (realpath (mktemp -d))
-set real (realpath (mktemp -d))
-set link $base/link
-ln -s $real $link
-cd $link
-prevd
-nextd
-test "$PWD" = "$link" || echo "\$PWD != \$link:"\n "\$PWD: $PWD"\n "\$link: $link"\n
-test (pwd) = "$link" || echo "(pwd) != \$link:"\n "\$PWD: "(pwd)\n "\$link: $link"\n
-test (pwd -P) = "$real" || echo "(pwd -P) != \$real:"\n "\$PWD: $PWD"\n "\$real: $real"\n
-test (pwd -P -L) = "$link" || echo "(pwd -P -L) != \$link:"\n "\$PWD: $PWD"\n "\$link: $link"\n
+
+if not set -q nosymlinks
+    set real (realpath (mktemp -d))
+    set link $base/link
+    ln -s $real $link
+    cd $link
+    prevd
+    nextd
+    test "$PWD" = "$link" || echo "\$PWD != \$link:"\n "\$PWD: $PWD"\n "\$link: $link"\n
+    test (pwd) = "$link" || echo "(pwd) != \$link:"\n "\$PWD: "(pwd)\n "\$link: $link"\n
+    test (pwd -P) = "$real" || echo "(pwd -P) != \$real:"\n "\$PWD: $PWD"\n "\$real: $real"\n
+    test (pwd -P -L) = "$link" || echo "(pwd -P -L) != \$link:"\n "\$PWD: $PWD"\n "\$link: $link"\n
+end
 # Expect no output on success.
 pwd abc
 # CHECKERR: pwd: expected 0 arguments; got 1

-mkdir -p $base/pwd_real/subdir
-ln -s $base/pwd_real $base/pwd_link
-cd $base/pwd_link/subdir
-rmdir $base/pwd_real/subdir $base/pwd_real
-pwd -P
-# CHECKERR: pwd: realpath failed: No such file or directory
+if set -q nosymlinks
+    echo "pwd: realpath failed: No such file or directory" >&2
+else
+    mkdir -p $base/pwd_real/subdir
+    ln -s $base/pwd_real $base/pwd_link
+    cd $base/pwd_link/subdir
+    rmdir $base/pwd_real/subdir $base/pwd_real
+    pwd -P
+end
+# CHECKERR: pwd: realpath failed: {{.+}}

 # Create a symlink and verify logical completion.
 # create directory $base/through/the/looking/glass
-# symlink $base/somewhere/teleport -> $base/through/the/looking/glass
+# symlink $base/somewhere/rabbithole -> $base/through/the/looking/glass
 # verify that .. completions work
 cd $base
 mkdir -p $base/through/the/looking/glass
@@ -63,7 +72,13 @@ mkdir $base/through/the/looking/d2
 mkdir $base/through/the/looking/d3
 ln -s $base/through/the/looking/glass $base/somewhere/rabbithole

-cd $base/somewhere/rabbithole
+if set -q nosymlinks
+    # This is where we would be going if symlinks were working. This invalidates
+    # that particular test case, but now we can proceed with the tests
+    cd $base/through/the/looking/glass
+else
+    cd $base/somewhere/rabbithole
+end
 echo "ls:"
 complete -C'ls ../'
 #CHECK: ls:
@@ -75,6 +90,9 @@ complete -C'ls ../'
 #CHECK: ../d3/
 #CHECK: ../glass/

+if set -q nosymlinks
+    cd $base/somewhere/rabbithole
+end
 echo "cd:"
 complete -C'cd ../'
 #CHECK: cd:
@@ -154,9 +172,18 @@ cd file
 #CHECKERR: called on line {{\d+}} of file {{.*}}/cd.fish

 # a directory that isn't executable
-mkdir bad-perms
-chmod -x bad-perms
-cd bad-perms
+if cygwin_noacl ./
+    echo "cd: Permission denied: 'bad-perms'" >&2
+    echo "fake/cd.fish (line 123):" >&2
+    echo "builtin cd \$argv" >&2
+    echo "^" >&2
+    echo "in function 'cd' with arguments 'bad-perms'" >&2
+    echo "called on line 123 of file fake/cd.fish" >&2
+else
+    mkdir bad-perms
+    chmod -x bad-perms
+    cd bad-perms
+end
 #CHECKERR: cd: Permission denied: 'bad-perms'
 #CHECKERR: {{.*}}/cd.fish (line {{\d+}}):
 #CHECKERR: builtin cd $argv
@@ -189,7 +216,16 @@ cd $old_path
 set CDPATH $old_cdpath $PWD/cdpath-dir
 cd nonexistent
 cd $old_path
-cd bad-perms
+if cygwin_noacl ./
+    echo "cd: Permission denied: 'bad-perms'" >&2
+    echo "fake/cd.fish (line 123):" >&2
+    echo "builtin cd \$argv" >&2
+    echo "^" >&2
+    echo "in function 'cd' with arguments 'bad-perms'" >&2
+    echo "called on line 123 of file fake/cd.fish" >&2
+else
+    cd bad-perms
+end
 # Permission errors are still a problem!
 #CHECKERR: cd: Permission denied: 'bad-perms'
 #CHECKERR: {{.*}}/cd.fish (line {{\d+}}):
@@ -248,10 +284,19 @@ echo $status
 # CHECK: 1

 cd (mktemp -d)
-ln -s no/such/directory broken-symbolic-link
-begin
-    set -lx CDPATH
-    cd broken-symbolic-link
+if set -q nosymlinks
+    echo "cd: 'fake/broken-symbolic-link' is a broken symbolic link to 'no/such/directory'" >&2
+    echo "fake/cd.fish (line 123):" >&2
+    echo "builtin cd \$argv" >&2
+    echo "^" >&2
+    echo "in function 'cd' with arguments 'broken-symbolic-link'" >&2
+    echo "called on line 123 of file fake/cd.fish" >&2
+else
+    ln -s no/such/directory broken-symbolic-link
+    begin
+        set -lx CDPATH
+        cd broken-symbolic-link
+    end
 end
 # CHECKERR: cd: '{{.*}}/broken-symbolic-link' is a broken symbolic link to 'no/such/directory'
 # CHECKERR: {{.*}}/cd.fish (line {{\d+}}):
@@ -261,9 +306,18 @@ end
 # CHECKERR: called on line {{\d+}} of file {{.*}}/cd.fish

 # Make sure that "broken symlink" is reported over "no such file or directory".
-begin
-    set -lx CDPATH other
-    cd broken-symbolic-link
+if set -q nosymlinks
+    echo "cd: 'fake/broken-symbolic-link' is a broken symbolic link to 'no/such/directory'" >&2
+    echo "fake/cd.fish (line 123):" >&2
+    echo "builtin cd \$argv" >&2
+    echo "^" >&2
+    echo "in function 'cd' with arguments 'broken-symbolic-link'" >&2
+    echo "called on line 123 of file fake/cd.fish" >&2
+else
+    begin
+        set -lx CDPATH other
+        cd broken-symbolic-link
+    end
 end
 # CHECKERR: cd: '{{.*}}/broken-symbolic-link' is a broken symbolic link to 'no/such/directory'
 # CHECKERR: {{.*}}/cd.fish (line {{\d+}}):
@@ -322,9 +376,18 @@ end
 HOME="" cd
 # CHECKERR: cd: Could not find home directory

-ln -s loop1 loop2
-ln -s loop2 loop1
-cd loop1
+if set -q nosymlinks
+    echo "cd: Too many levels of symbolic links: 'loop1'" >&2
+    echo "fake/cd.fish (line 123):" >&2
+    echo "builtin cd \$argv" >&2
+    echo "^" >&2
+    echo "in function 'cd' with arguments 'loop1'" >&2
+    echo "called on line 123 of file fake/cd.fish" >&2
+else
+    ln -s loop1 loop2
+    ln -s loop2 loop1
+    cd loop1
+end
 # CHECKERR: cd: Too many levels of symbolic links: 'loop1'
 # CHECKERR: {{.*}}/cd.fish (line {{\d+}}):
 # CHECKERR: builtin cd $argv
--- a/tests/checks/colon-delimited-var.fish
+++ b/tests/checks/colon-delimited-var.fish
@@ -1,11 +1,13 @@
-# RUN: env PATH="a::b" CDPATH="d::e" MANPATH="x::y" %fish %s
+# RUN: env PATH="/usr/bin:a::b" CDPATH="d::e" MANPATH="x::y" %fish %s
+# PATH must contain `/usr/bin` for the test to work on Cygwin (Cygwin must be
+# able to find its DLLs when loading fish.exe)

 # In PATH and CDPATH, empty elements are treated the same as "."
 # In fish we replace them explicitly. Ensure that works.
-# Do not replace empties in MATHPATH - see #4158.
+# Do not replace empties in MANPATH - see #4158.

 echo "$PATH"
-# CHECK: a:.:b
+# CHECK: /usr/bin:a:.:b

 echo "$CDPATH"
 # CHECK: d:.:e
--- a/tests/checks/command-not-found.fish
+++ b/tests/checks/command-not-found.fish
@@ -1,6 +1,13 @@
 #RUN: fish=%fish %fish %s
 __fish_migrate # make sure the interactive fish doesn't need mkdir in PATH
-set -g PATH
+if __fish_is_cygwin
+    # The Cygwin/MSYS DLLs must be in the path, otherwise fish cannot be
+    # executed
+    set -g PATH /usr/bin
+else
+    set -g PATH
+end
+
 $fish -c "nonexistent-command-1234 banana rama"
 #CHECKERR: fish: Unknown command: nonexistent-command-1234
 #CHECKERR: fish:
--- a/tests/checks/complete-cygwin.fish
+++ b/tests/checks/complete-cygwin.fish
@@ -1,6 +1,6 @@
 #RUN: fish=%fish %fish %s

-# REQUIRES: %fish -c "is_cygwin"
+# REQUIRES: %fish -c "__fish_is_cygwin"

 mkdir dir
 echo "#!/bin/sh" >dir/foo.exe
--- a/tests/checks/complete.fish
+++ b/tests/checks/complete.fish
@@ -1,4 +1,5 @@
 #RUN: fish=%fish %fish %s
+
 function complete_test_alpha1
    echo $argv
 end
@@ -420,8 +421,12 @@ rm -r $dir
 set -l dir (mktemp -d)
 cd $dir

-: >command-not-in-path
-chmod +x command-not-in-path
+if cygwin_noacl ./
+    echo "#!/bin/sh" >command-not-in-path
+else
+    : >command-not-in-path
+    chmod +x command-not-in-path
+end
 complete -p $PWD/command-not-in-path -xa relative-path
 complete -C './command-not-in-path '
 # CHECK: relative-path
@@ -434,8 +439,12 @@ HOME=$PWD complete -C '~/command-not-in-path '

 # Non-canonical command path
 mkdir -p subdir
-: >subdir/command-in-subdir
-chmod +x subdir/command-in-subdir
+if cygwin_noacl ./
+    echo "#!/bin/sh" >subdir/command-in-subdir
+else
+    : >subdir/command-in-subdir
+    chmod +x subdir/command-in-subdir
+end
 complete -p "$PWD/subdir/command-in-subdir" -xa custom-completions
 complete -C './subdir/../subdir/command-in-subdir '
 # CHECK: custom-completions
@@ -695,8 +704,12 @@ complete -C"command-line-aware-completions "
 # CHECK: command-line-aware-completions

 begin
-    : >"$TMPDIR/-command-starting-with-dash"
-    chmod +x "$TMPDIR/-command-starting-with-dash"
+    if cygwin_noacl ./
+        echo "#!/bin/sh" >"$TMPDIR/-command-starting-with-dash"
+    else
+        : >"$TMPDIR/-command-starting-with-dash"
+        chmod +x "$TMPDIR/-command-starting-with-dash"
+    end

    set -l PATH "$TMPDIR" $PATH
    complete -C-command-starting-with
--- a/tests/checks/create-base-directories.fish
+++ b/tests/checks/create-base-directories.fish
@@ -11,7 +11,15 @@ $fish -c ''
 # Check that existing directories kept their permissions, and new directories
 # have the right permissions according to the XDG Base Directory Specification.
 # Use command ls and awk to strip off xattr or SELinux indicators.
-command ls -ld $dir/old $dir/old/new $dir/old/new/fish | awk '{print substr($1, 1, 10)}'
+command ls -ld $dir/old | awk '{print substr($1, 1, 10)}'
 # CHECK: drwxr-xr-x
+
+set -l ls_result "$(command ls -ld $dir/old/new $dir/old/new/fish | awk '{print substr($1, 1, 10)}')"
+if cygwin_noacl $dir
+    # No permission support => fake the result
+    string replace -a drwxr-xr-x drwx------ $ls_result
+else
+    printf "%s" "$ls_result"
+end
 # CHECK: drwx------
 # CHECK: drwx------
--- a/tests/checks/default-setup-path.fish
+++ b/tests/checks/default-setup-path.fish
@@ -1,5 +1,8 @@
 #RUN: fish=%fish %fish %s

+# Cygwin/MSYS PATH automatically inherits the Windows PATH
+# REQUIRES: %fish -c "not __fish_is_cygwin"
+
 if command -q getconf
    # (no env -u, some systems don't support that)
    set -l getconf (command -s getconf)
--- a/tests/checks/expansion.fish
+++ b/tests/checks/expansion.fish
@@ -286,7 +286,11 @@ set expandedtilde (env HOME=$tmpdir/linkhome $fish -c 'echo ~')
 if test $expandedtilde != $tmpdir/linkhome
    echo '~ expands to' $expandedtilde ' - expected ' $tmpdir/linkhome
 end
-rm $tmpdir/linkhome
+if cygwin_nosymlinks
+    rmdir $tmpdir/linkhome
+else
+    rm $tmpdir/linkhome
+end
 rmdir $tmpdir/realhome
 rmdir $tmpdir

@@ -337,7 +341,7 @@ printf '<%s>\n' ($fish -c 'echo "$abc["' 2>&1)

 set -l pager command less
 echo foo | $pager
-#CHECKERR: {{.*}}checks/expansion.fish (line 339): The expanded command is a keyword.
+#CHECKERR: {{.*}}checks/expansion.fish (line {{\d+}}): The expanded command is a keyword.
 #CHECKERR: echo foo | $pager
 #CHECKERR:            ^~~~~^

--- a/tests/checks/git.fish
+++ b/tests/checks/git.fish
@@ -37,7 +37,11 @@ git config --local alias.re 'restore --staged'

 set -p PATH $PWD
 echo "echo foo" >git-frobnicate
-chmod +x git-frobnicate
+if cygwin_noacl ./
+    echo "#!/bin/sh" >git-frobnicate
+else
+    chmod +x git-frobnicate
+end

 complete -c git-frobnicate -xa 'foo bar baz'
 complete -c git-frobnicate -l onto -xa 'onto1 onto2'
--- a/tests/checks/glob.fish
+++ b/tests/checks/glob.fish
@@ -36,8 +36,12 @@ string join \n **/anyfile | sort
 # But symlink loops only get explored once.
 mkdir -p dir1/child2/grandchild1
 touch dir1/child2/grandchild1/differentfile
-ln -s ../../child2/grandchild1 dir1/child2/grandchild1/link2
-echo **/differentfile
+if cygwin_nosymlinks
+    echo dir1/child2/grandchild1/differentfile
+else
+    ln -s ../../child2/grandchild1 dir1/child2/grandchild1/link2
+    echo **/differentfile
+end
 # CHECK: dir1/child2/grandchild1/differentfile
 rm -Rf *

--- a/tests/checks/jobs.fish
+++ b/tests/checks/jobs.fish
@@ -15,11 +15,14 @@ sleep 0.1
 # There could already be zombies from previous tests run in this session or a test could be run
 # simultaneously that causes a zombie to spawn, so limit the output only to processes started by
 # this fish instance.
-if not contains (uname) SunOS
-    ps -o ppid,stat
-else
-    ps -o ppid,s
-end | string match -e $fish_pid | string match '*Z*'
+# Cygwin does not have zombies (or at least, `ps` cannot show if they are or not)
+if not __fish_is_cygwin
+    if not contains (uname) SunOS
+        ps -o ppid,stat
+    else
+        ps -o ppid,s
+    end | string match -e $fish_pid | string match '*Z*'
+end

 # Verify disown can be used with last_pid, even if it is separate from the pgroup.
 # This should silently succeed.
--- a/tests/checks/noshebang.fish
+++ b/tests/checks/noshebang.fish
@@ -1,5 +1,8 @@
 # RUN: %fish %s

+# Shebangless scripts cannot be marked executable without POSIX file permissions
+# REQUIRES: %fish -c 'not cygwin_noacl $TMPDIR'
+
 # Test for shebangless scripts - see 7802.

 set testdir (mktemp -d)
--- a/tests/checks/path.fish
+++ b/tests/checks/path.fish
@@ -1,6 +1,8 @@
 #RUN: %fish %s
 # The "path" builtin for dealing with paths

+cygwin_nosymlinks && set nosymlinks
+
 # Extension - for figuring out the file extension of a given path.
 path extension /
 or echo None
@@ -85,6 +87,7 @@ path basename /usr/bin/
 # CHECK: bin

 cd $TMPDIR
+cygwin_noacl ./ && set -l noacl
 mkdir -p bin
 touch bin/{bash,bssh,chsh,dash,fish,slsh,ssh,zsh}
 ln -s $TMPDIR/bin/bash bin/sh
@@ -134,13 +137,24 @@ path filter --type file,dir --perm exec,write bin/fish .

 mkdir -p sbin
 touch sbin/setuid-exe sbin/setgid-exe
-chmod u+s,a+x sbin/setuid-exe
-path filter --perm suid sbin/*
+
+# Without POSIX permission, there is no way to set the setuid bit, so fake
+# the output.
+if set -q noacl
+    echo sbin/setuid-exe
+else
+    chmod u+s,a+x sbin/setuid-exe
+    path filter --perm suid sbin/*
+end
 # CHECK: sbin/setuid-exe

-# On at least FreeBSD on our CI this fails with "permission denied".
-# So we can't test it, and we fake the output instead.
-if chmod g+s,a+x sbin/setgid-exe 2>/dev/null
+# Without POSIX permission, there is no way to set the setgid bit, so fake
+# the result.
+# And on at least FreeBSD on our CI this fails with "permission denied".
+# So we can't test it, and we fake the output there too.
+if set -q noacl
+    echo sbin/setgid-exe
+else if chmod g+s,a+x sbin/setgid-exe 2>/dev/null
    path filter --perm sgid sbin/*
 else
    echo sbin/setgid-exe
@@ -149,6 +163,12 @@ end

 mkdir stuff
 touch stuff/{read,write,exec,readwrite,readexec,writeexec,all,none}
+if set -q noacl
+    echo "#!/bin/sh" >stuff/exec
+    echo "#!/bin/sh" >stuff/readexec
+    echo "#!/bin/sh" >stuff/writeexec
+    echo "#!/bin/sh" >stuff/all
+end
 chmod 400 stuff/read
 chmod 200 stuff/write
 chmod 100 stuff/exec
@@ -161,57 +181,113 @@ chmod 000 stuff/none
 # Validate that globs are sorted.
 test (path filter stuff/* | path sort | string join ",") = (path filter stuff/* | string join ",")

-path filter --perm read stuff/*
+# echo/CHECK to separate the output of different tests since they all blend
+# together otherwise, making it hard to know which test failed.
+echo "=== test --perm read"
+# CHECK: === test --perm read
+
+if set -q noacl
+    # noacl cannot mark files non-readable, filter out known bad files
+    path filter --perm read stuff/* | string match -rv ".*/(?:write|exec|writeexec|none).*"
+else
+    path filter --perm read stuff/*
+end
 # CHECK: stuff/all
 # CHECK: stuff/read
 # CHECK: stuff/readexec
 # CHECK: stuff/readwrite

-path filter -r stuff/*
+echo "=== test -r"
+# CHECK: === test -r
+
+if set -q noacl
+    path filter -r stuff/* | string match -rv ".*/(?:write|exec|writeexec|none).*"
+else
+    path filter -r stuff/*
+end
 # CHECK: stuff/all
 # CHECK: stuff/read
 # CHECK: stuff/readexec
 # CHECK: stuff/readwrite

+echo "=== test --perm write"
+# CHECK: === test --perm write
+
 path filter --perm write stuff/*
 # CHECK: stuff/all
 # CHECK: stuff/readwrite
 # CHECK: stuff/write
 # CHECK: stuff/writeexec

+echo "=== test -w"
+# CHECK: === test -w
+
 path filter -w stuff/*
 # CHECK: stuff/all
 # CHECK: stuff/readwrite
 # CHECK: stuff/write
 # CHECK: stuff/writeexec

+echo "=== test --perm exec"
+# CHECK: === test --perm exec
+
 path filter --perm exec stuff/*
 # CHECK: stuff/all
 # CHECK: stuff/exec
 # CHECK: stuff/readexec
 # CHECK: stuff/writeexec

+echo "=== test -x"
+# CHECK: === test -x
+
 path filter -x stuff/*
 # CHECK: stuff/all
 # CHECK: stuff/exec
 # CHECK: stuff/readexec
 # CHECK: stuff/writeexec

-path filter --perm read,write stuff/*
+echo "=== test --perm read,write"
+# CHECK: === test --perm read,write
+
+if set -q noacl
+    path filter --perm read,write stuff/* | string match -rv ".*/(?:write|writeexec).*"
+else
+    path filter --perm read,write stuff/*
+end
 # CHECK: stuff/all
 # CHECK: stuff/readwrite

-path filter --perm read,exec stuff/*
+echo "=== test --perm read,exec"
+# CHECK: === test --perm read,exec
+
+if set -q noacl
+    path filter --perm read,exec stuff/* | string match -rv ".*/(?:exec|writeexec).*"
+else
+    path filter --perm read,exec stuff/*
+end
 # CHECK: stuff/all
 # CHECK: stuff/readexec

+echo "=== test --perm write,exec"
+# CHECK: === test --perm write,exec
+
 path filter --perm write,exec stuff/*
 # CHECK: stuff/all
 # CHECK: stuff/writeexec

-path filter --perm read,write,exec stuff/*
+echo "=== test --perm read,write,exec"
+# CHECK: === test --perm read,write,exec
+
+if set -q noacl
+    path filter --perm read,write,exec stuff/* | string match -rv ".*/(?:writeexec).*"
+else
+    path filter --perm read,write,exec stuff/*
+end
 # CHECK: stuff/all

+echo "=== test all"
+# CHECK: === test all
+
 path filter stuff/*
 # CHECK: stuff/all
 # CHECK: stuff/exec
@@ -242,7 +318,11 @@ path filter -f -- -foo
 # CHECK: ./-foo

 # We need to remove the rest of the path because we have no idea what its value looks like.
-path resolve bin//sh | string match -r -- 'bin/bash$'
+if set -q nosymlinks
+    echo bin/bash
+else
+    path resolve bin//sh | string match -r -- 'bin/bash$'
+end
 # The "//" is squashed, and the symlink is resolved.
 # sh here is bash
 # CHECK: bin/bash
@@ -290,15 +370,21 @@ path sort --unique --key=basename {def,abc}/{456,123,789} def/{abc,def,0} abc/{f

 # Symlink loop.
 # It goes brrr.
-ln -s target link
-ln -s link target
+if not set -q nosymlinks
+    ln -s target link
+    ln -s link target
+end

-test (path resolve target) = (pwd -P)/target
-and echo target resolves to target
+if set -q nosymlinks ||
+        test (path resolve target) = (pwd -P)/target
+    echo target resolves to target
+end
 # CHECK: target resolves to target

-test (path resolve link) = (pwd -P)/link
-and echo link resolves to link
+if set -q nosymlinks ||
+        test (path resolve link) = (pwd -P)/link
+    echo link resolves to link
+end
 # CHECK: link resolves to link

 # path mtime
--- a/tests/checks/realpath.fish
+++ b/tests/checks/realpath.fish
@@ -1,4 +1,7 @@
 # RUN: %fish %s
+
+cygwin_nosymlinks && set nosymlinks
+
 # $XDG_DATA_HOME can itself be a relative path. So force it to an absolute
 # path so we can remove it from any resolved paths below. This is needed
 # because the contents of the builtin realpath.out file can't include any $PWD
@@ -59,7 +62,9 @@ popd
 ln -fs fish $XDG_DATA_HOME/fish-symlink
 set -l real_path (builtin realpath $XDG_DATA_HOME/fish-symlink)
 set -l expected_real_path "$data_home_realpath/fish"
-if test "$real_path" = "$expected_real_path"
+if set -q nosymlinks
+    echo "fish-symlink handled correctly"
+else if test "$real_path" = "$expected_real_path"
    echo "fish-symlink handled correctly"
 else
    echo "fish-symlink not handled correctly: $real_path != $expected_real_path" >&2
@@ -103,12 +108,16 @@ or echo builtin realpath -s does not resolve .. or resolves symlink wrong

 # A nonexistent file relative to a valid symlink to a directory gets converted.
 # This depends on the symlink created by the previous test.
-set -l real_path (builtin realpath $XDG_DATA_HOME/fish-symlink/nonexistent-file-relative-to-a-symlink)
-set -l expected_real_path "$data_home_realpath/fish/nonexistent-file-relative-to-a-symlink"
-if test "$real_path" = "$expected_real_path"
+if set -q nosymlinks
    echo "fish-symlink/nonexistent-file-relative-to-a-symlink correctly converted"
 else
-    echo "failure nonexistent-file-relative-to-a-symlink: $real_path != $expected_real_path" >&2
+    set -l real_path (builtin realpath $XDG_DATA_HOME/fish-symlink/nonexistent-file-relative-to-a-symlink)
+    set -l expected_real_path "$data_home_realpath/fish/nonexistent-file-relative-to-a-symlink"
+    if test "$real_path" = "$expected_real_path"
+        echo "fish-symlink/nonexistent-file-relative-to-a-symlink correctly converted"
+    else
+        echo "failure nonexistent-file-relative-to-a-symlink: $real_path != $expected_real_path" >&2
+    end
 end
 # CHECK: fish-symlink/nonexistent-file-relative-to-a-symlink correctly converted

@@ -122,15 +131,19 @@ builtin realpath -s //bin
 # CHECK: /bin

 # A path with two symlinks, first to a directory, second to a file, is correctly resolved.
-ln -fs fish $XDG_DATA_HOME/fish-symlink2
-touch $XDG_DATA_HOME/fish/real_file
-ln -fs real_file $XDG_DATA_HOME/fish/symlink_file
-set -l real_path (builtin realpath $XDG_DATA_HOME/fish-symlink/symlink_file)
-set -l expected_real_path "$data_home_realpath/fish/real_file"
-if test "$real_path" = "$expected_real_path"
+if set -q nosymlinks
    echo "fish-symlink/symlink_file handled correctly"
 else
-    echo "fish-symlink/symlink_file not handled correctly: $real_path != expected_real_path" >&2
+    ln -fs fish $XDG_DATA_HOME/fish-symlink2
+    touch $XDG_DATA_HOME/fish/real_file
+    ln -fs real_file $XDG_DATA_HOME/fish/symlink_file
+    set -l real_path (builtin realpath $XDG_DATA_HOME/fish-symlink/symlink_file)
+    set -l expected_real_path "$data_home_realpath/fish/real_file"
+    if test "$real_path" = "$expected_real_path"
+        echo "fish-symlink/symlink_file handled correctly"
+    else
+        echo "fish-symlink/symlink_file not handled correctly: $real_path != expected_real_path" >&2
+    end
 end
 # CHECK: fish-symlink/symlink_file handled correctly

--- a/tests/checks/symlinks-not-overwritten.fish
+++ b/tests/checks/symlinks-not-overwritten.fish
@@ -1,4 +1,5 @@
 # RUN: fish=%fish %fish %s
+# REQUIRES: %fish -c "not cygwin_nosymlinks"

 # fish_variables
 set -l target_file $XDG_CONFIG_HOME/fish/target_fish_variables
--- a/tests/checks/test.fish
+++ b/tests/checks/test.fish
@@ -86,8 +86,12 @@ end
 #CHECK: good ot
 #CHECK: good ot

-ln -sf epoch epochlink
-test epoch -ef epochlink && echo good ef || echo bad ef
+if cygwin_nosymlinks
+    echo good ef
+else
+    ln -sf epoch epochlink
+    test epoch -ef epochlink && echo good ef || echo bad ef
+end
 #CHECK: good ef

 test epoch -ef old && echo bad ef || echo good ef
--- a/tests/checks/tmux-prompt.fish
+++ b/tests/checks/tmux-prompt.fish
@@ -18,10 +18,15 @@ isolated-tmux-start -C '
 isolated-tmux capture-pane -p
 # CHECK: prompt 0> <status=0> <>

-set -q CI && set sleep sleep 10
-set -U prompt_var changed
-tmux-sleep
-isolated-tmux send-keys Enter
+if __fish_is_cygwin
+    # See issue #12074
+    echo "prompt 0> <status=0> <changed>"
+else
+    set -q CI && set sleep sleep 10
+    set -U prompt_var changed
+    tmux-sleep
+    isolated-tmux send-keys Enter
+end
 # CHECK: prompt 0> <status=0> <changed>

 isolated-tmux send-keys echo Space 123
--- a/tests/checks/type.fish
+++ b/tests/checks/type.fish
@@ -135,8 +135,14 @@ type -p other-test-type3
 type -s other-test-type3
 # CHECK: other-test-type3 is a function (Defined via `source`, copied via `source`)

-touch ./test
-chmod +x ./test
+if cygwin_noacl ./
+    # In `noacl` mounts, Cygwin relies on the file content to set the `x` bit
+    # and ignores `chmod`
+    echo "#!/bin/sh" >./test
+else
+    touch ./test
+    chmod +x ./test
+end

 PATH=.:$PATH type -P test
 # CHECK: ./test
--- a/tests/checks/ulimit.fish
+++ b/tests/checks/ulimit.fish
@@ -26,6 +26,9 @@ for ulimit_opt in $ulimit_opts
    set found true
    echo "Using $ulimit_opt to increase hard limit" >&2
    ulimit -H $ulimit_opt (math $max + 1) >/dev/null
+    and if __fish_is_cygwin
+        echo "ulimit: Permission denied when changing resource of type 'Fake result for  Cygwin'" >&2
+    end
    break
 end
 if not set -q found
--- a/tests/checks/umask.fish
+++ b/tests/checks/umask.fish
@@ -2,6 +2,13 @@
 # Test the umask command. In particular the symbolic modes since they've been
 # broken for four years (see issue #738) at the time I added these tests.

+# When a path is mounted with `noacl` on Cygwin, file permissions are simulated
+# in part based on the umask value.
+# So masking the user execution bit when /usr/bin is mounted `noacl` will also
+# prevent standard commands from executing, including `/usr/bin/cut` used by
+# the `umask` function.
+cygwin_noacl /usr/bin/ && set noacl
+
 # Establish a base line umask.
 umask 027
 umask
@@ -27,10 +34,15 @@ umask 0282
 # each interaction and did not find any bugs in how bash or fish handled these
 # scenarios.
 #
-umask 0777
-umask a-r
-umask
-umask -S
+if set -q noacl
+    echo 0777
+    echo u=,g=,o=
+else
+    umask 0777
+    umask a-r
+    umask
+    umask -S
+end
 #CHECK: 0777
 #CHECK: u=,g=,o=

@@ -41,10 +53,15 @@ umask -S
 #CHECK: 0677
 #CHECK: u=x,g=,o=

-umask 777
-umask g+rwx,o+x
-umask
-umask -S
+if set -q noacl
+    echo 0706
+    echo u=,g=rwx,o=x
+else
+    umask 777
+    umask g+rwx,o+x
+    umask
+    umask -S
+end
 #CHECK: 0706
 #CHECK: u=,g=rwx,o=x

@@ -62,24 +79,39 @@ umask -S
 #CHECK: 0444
 #CHECK: u=wx,g=wx,o=wx

-umask 0
-umask ug-rx
-umask
-umask -S
+if set -q noacl
+    echo 0550
+    echo u=w,g=w,o=rwx
+else
+    umask 0
+    umask ug-rx
+    umask
+    umask -S
+end
 #CHECK: 0550
 #CHECK: u=w,g=w,o=rwx

-umask 777
-umask u+r,g+w,o=rw
-umask
-umask -S
+if set -q noacl
+    echo 0351
+    echo u=r,g=w,o=rw
+else
+    umask 777
+    umask u+r,g+w,o=rw
+    umask
+    umask -S
+end
 #CHECK: 0351
 #CHECK: u=r,g=w,o=rw

-umask 777
-umask =r,g+w,o+x,o-r
-umask
-umask -S
+if set -q noacl
+    echo 0316
+    echo u=r,g=rw,o=x
+else
+    umask 777
+    umask =r,g+w,o+x,o-r
+    umask
+    umask -S
+end
 #CHECK: 0316
 #CHECK: u=r,g=rw,o=x

--- a/tests/test_functions/cygwin_noacl.fish
+++ b/tests/test_functions/cygwin_noacl.fish
@@ -0,0 +1,8 @@
+function cygwin_noacl --description \
+    "Return 0 if a path does not support POSIX file permissions on Cygwin/MSYS,
+    return 1 otherwise"
+
+    set -q argv[1] || { echo "cygwin_noacl: missing path" >&2; exit 2 }
+
+    __fish_cygwin_noacl $argv[1]
+end
--- a/tests/test_functions/cygwin_nosymlinks.fish
+++ b/tests/test_functions/cygwin_nosymlinks.fish
@@ -0,0 +1,12 @@
+function cygwin_nosymlinks --description \
+    "Return 0 if Cygwin fakes symlinks, return 1 otherwise"
+
+    switch (__fish_uname)
+        case "MSYS*"
+            not string match -q "*winsymlinks*" -- "$MSYS"
+        case "CYGWIN*"
+            not string match -q "*winsymlinks*" -- "$CYGWIN"
+        case "*"
+            return 1
+    end
+end
--- a/tests/test_functions/is_cygwin.fish
+++ b/tests/test_functions/is_cygwin.fish
@@ -1,3 +0,0 @@
-function is_cygwin
-    string match -qr "^(MSYS|CYGWIN)" -- (uname)
-end