gh-151042: venv: Pass VIRTUAL_ENV through cygpath inside fish on Windows (GH-151043)

Author: LuNoX

Lib/venv/scripts/common/activate.fish

@@ -34,6 +34,9 @@ end
 deactivate nondestructive
 
 set -gx VIRTUAL_ENV __VENV_DIR__
+if string match -qr 'CYGWIN|MSYS|MINGW' (uname)
+    set -gx VIRTUAL_ENV (cygpath -u $VIRTUAL_ENV)
+end
 
 set -gx _OLD_VIRTUAL_PATH $PATH
 set -gx PATH "$VIRTUAL_ENV/"__VENV_BIN_NAME__ $PATH

Misc/NEWS.d/next/Library/2026-06-07-13-47-05.gh-issue-151042.NMdzF2.rst

@@ -0,0 +1 @@
+Fixed venv exporting mixed path styles to PATH on Windows inside fish (via Cygwin, MinGW or MSYS2)