Warn if command-not-found because it's not executable

[EdmundsEcho]

I have several directories in my PATH. I can see the path required to access the binary of interest. For some reason, I cannot get fish to find the binary.

The PATH

The path of interest is /opt/homebrew/bin

echo $PATH
/Users/edmund/.asdf/shims /Users/edmund/.asdf/bin /Users/edmund/.local/share/nvm/v16.14.1/bin /Users/edmund/.deno/bin /Users/edmund/.yarn/bin /Users/edmund/.local/bin /opt/homebrew/opt/llvm/bin /Users/edmund/.pyenv/shims /Users/edmund/.pyenv/bin /opt/homebrew/sbin **/opt/homebrew/bin** /usr/local/bin /usr/bin /bin /usr/sbin /sbin /Users/edmund/.krew/bin /Users/edmund/.ghcup/bin /Users/edmund/.cargo/bin /opt/homebrew/opt/findutils/libexec/gnubin /opt/homebrew/opt/make/libexec/gnubin /opt/homebrew/opt/gawk/libexec/gnubin /opt/homebrew/opt/gsed/libexec/gnubin /opt/homebrew/opt/gnu-sed/libexec/gnubin /opt/homebrew/opt/grep/libexec/gnubin /opt/homebrew/opt/ed/libexec/gnubin /opt/homebrew/opt/gnu-tar/libexec/gnubin /opt/homebrew/opt/coreutils/libexec/gnubin /opt/homebrew/opt/libtool/libexec/gnubin

The content of that path

Note the presence of yarn

> ls /opt/homebrew/bin | ggrep yarn
yarn
yarnpkg

Fish not finding the binary

> yarn
fish: Unknown command: yarn

> which yarn
<empty line>

Other binaries can be found...

Fish can find other binaries in the same path (e.g., jq is in the directory)

> ls /opt/homebrew/bin | ggrep jq
jq

> which jq
/opt/homebrew/bin/jq

The question

What might prevent fish from finding the binary? (in this case yarn). How might I go about problem solving this?

Thank you in advance.

- E

[zanchey]

You could see what the permissions on the file are:

stat /opt/homebrew/bin/yarn

The output of contains /opt/homebrew/bin $PATH will confirm that the path is set right.

[ridiculousfish]

Just to be sure, your $PATH does not actually contain:

**/opt/homebrew/bin**

including the asterisks? fish does not expand globs in $PATH.

[EdmundsEcho]

@ridiculousfish -- correct :))

... per the suggestion use of contains (thank you @zanchey)

> if contains /opt/homebrew/bin $PATH; echo 'present'; else; echo 'missing'; end;
present

[faho]

@EdmundsEcho In that case it appears /opt/homebrew/bin/yarn isn't executable by you. Which is why zanchey asked for you to run stat - that would include the permissions (but I'm not sure it's a thing on macOS).

I'm assuming test -x /opt/homebrew/bin/yarn; echo $status prints 1.

[EdmundsEcho]

@zanchey The permissions was the issue. I confirmed this by toggling the -/+x to in fact show how fish will not find the binary if the permission does not include x.

❯ chmod +x /opt/homebrew/bin/yarn

❯ which yarn
/opt/homebrew/bin/yarn

❯ chmod -x /opt/homebrew/bin/yarn
<empty line>

This behavior is a "norm" given that I can replicate it in bash.

This said, should it be a norm?

Receiving an error is in-line with what I would have intuited.

• Is there a way for the shell to report something like a "execute permission denied"?

• Would reporting such an error be a breaking-change for scripts that don't expect a return value in the event the permissions are missing?

• Otherwise, might the difference between the empty response and the error be a useful hook allowing the programmer to "intervene" accordingly?

[EdmundsEcho]

I'm assuming test -x /opt/homebrew/bin/yarn; echo $status prints 1.

@faho You got it. This is helpful. Thank you.

[faho]

Okay, here's what we can do:

If you try to execute a command, and none is found, we go through $PATH and try to find a file. If it's not executable, we print that with the command-not-found error.

In this specific case, it would have printed:

fish: Unknown command: yarn
fish: /opt/homebrew/bin/yarn exists but isn't executable