fix: chmod permission error when nix-direnv-reload owned by different user #647
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…user Use `install -m 755` instead of separate cat + chmod to atomically create the file with correct permissions. This works even when an existing file is owned by another user (e.g., root), as install unlinks and recreates the file. Assisted-By: claude-opus-4-5-20251101 via Claude Code
Contributor
| Has this fix been tested on Darwin? I worry about its options not matching a nixos or Linux provided binaries. |
Author
Good point. I ran some tests and found this to be a darwin-compatible version: # Good (tested on Linux + macOS) install -m 755 /dev/stdin "$target" <<'EOF' ... EOFAnother option would be to just remove the file (did that for devenv) - but I wasn't sure if that would maybe reset other kinds of permissions. (But the file is created by "us" anyways, right? so we could just remove and recreate?) |
tennox added a commit to tennox/devenv that referenced this pull request Dec 12, 2025
The previous pipe-based approach (printf | install /dev/stdin) doesn't work reliably on macOS. Use temp file + install instead, which: - Preserves exact contents of DEVENV_TASK_ENV (no shell expansion) - Fixes file-owned-by-another-user problem (install recreates) - Works on both Linux and macOS See: nix-community/nix-direnv#647 (comment) Assisted-By: claude-opus-4-5-20251101 via Claude Code
tennox added a commit to tennox/devenv that referenced this pull request Dec 12, 2025
The pipe-based `echo | install /dev/stdin` approach doesn't work reliably on macOS (piping to /dev/stdin fails on Darwin). Simply removing the file first achieves the same result: rm succeeds on files owned by other users (only needs directory write permission), then echo + chmod work on the newly created file we own. See: nix-community/nix-direnv#647 (comment) Assisted-By: claude-opus-4-5-20251101 via Claude Code
1 task
Contributor
| Let's just do this the same way as you implemented it for devenv, please. Just |
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Summary
Fix
chmod: Operation not permittederror whennix-direnv-reloadfile is owned by adifferent user (e.g., a colleague entered direnv first).
Problem
chmodcannot change permissions on a file owned by another user.Solution
Use
install -m 755 /dev/stdininstead of separatecat+chmod. Theinstallcommandunlinks and recreates the file rather than modifying it in place, which works even when the
existing file is owned by another user.
Test
Add this to
.envrc: