ci: Prevent fish from creating tempfiles

.gitignore

@@ -8,9 +8,8 @@
 
 # Project
 /.circleci/.config.yml
-.download
-bin
-man
+/bin
+/man
 
 # Side-Effects
 /test/data/.config/fish

test/shimexec/fish

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+# Find the real fish.
+HERE="$(cd "$(dirname "$0")" && pwd)"
+while read -d ':' -r dir; do
+	if [[ "$dir" == "$HERE" || -z "$dir" ]]; then continue; fi
+	if [[ -f "${dir}/fish" ]]; then
+		TMPDIR= "${dir}/fish" "$@"
+		exit $?
+	fi
+done <<<"$PATH:"
+
+# Print error and exit.
+echo "fish was not found on \$PATH" 1>&2
+exit 127