env: 'foo bar': No such file or directory

I write my agent prompts as executable files. They start like this:

#!/usr/bin/env claude-run --allow-write

claude-run is my own wrapper. It runs a prompt file and stays read-only unless you pass --allow-write.

This worked on my Mac. I deployed to an Oracle Linux ARM box and got:

/usr/bin/env: 'claude-run --allow-write': No such file or directory

The file was there. It was on PATH. I could run it by hand. I spent 45 minutes on this.

What’s happening

Linux reads everything after #!/usr/bin/env as one argument. So env goes looking for a program called claude-run --allow-write, space included. There is no such program, so it tells you there’s no such file.

BSD env, which is what macOS ships, splits on spaces. So the same script works on the Mac and fails on Linux.

The fix

GNU env has a flag for this. It’s -S, for split:

#!/usr/bin/env -S claude-run --allow-write

I updated ten scripts with one sed:

sed -i 's|#!/usr/bin/env |#!/usr/bin/env -S |g' claude-scripts/*.ai

macOS has supported -S since Big Sur, so the same line now works in both places. Older macOS can’t use -S. There, the usual workaround is a two-line wrapper script instead of a shebang.

Why it took 45 minutes

“No such file or directory” sent me to check the filesystem. I checked permissions. I reinstalled the thing. I did not think to look at the space.

If a script that definitely exists tells you it doesn’t, check whether your shebang has arguments in it.