Fish completion broken on macOS (BSD sed incompatibility)

[max-sixty]

Description

I think all fish completions are now broken on MacOS. Here's a reproducer, which Claude helped me write, and a link to the PR that I think created these changes.

---

What did you do?
Ran task <TAB> in fish shell on macOS to get task completions.

What did you expect to happen?

$ task <TAB>
clean  (Reset environment to declared dependencies.)

What happened instead?

$ task <TAB>
* clean:                         Reset environment to declared dependencies.  (Runs the specified task(s)...
* ```
Task names appear with raw formatting instead of clean completions.

**Cause:**
The `__task_get_tasks` function in `completion/fish/task.fish` uses:

```fish
sed -e '1d; s/\* \(.*\):\s\{2,\}\(.*\)\s\{2,\}(\(aliases.*\))/\1\t\2\t\3/' -e 's/\* \(.*\):\s\{2,\}\(.*\)/\1\t\2/'

The \s escape sequence (whitespace) is a GNU sed extension. BSD sed (macOS default) doesn't support it, so the pattern silently fails to match and passes through raw output.

Fix:
Replace \s\{2,\} with POSIX-compatible [[:space:]][[:space:]]* or simply * (two literal spaces followed by asterisk):

sed -e '1d; s/\* \(.*\):  *\(.*\)  *(\(aliases.*\))/\1\t\2\t\3/' -e 's/\* \(.*\):  *\(.*\)/\1\t\2/'

Tested on macOS 15.2 with BSD sed — the POSIX pattern correctly extracts task names and descriptions.

Note: Previous versions (before v3.46.1) used sed 's/: /\t/g' which was POSIX-compatible. The regression was introduced when PR #2532 rewrote the completion script.

Version

3.46.3 (introduced in v3.46.1)

Operating system

macOS 15.2 (Sequoia) with BSD sed

Experiments Enabled

No response

Example Taskfile

[vmaerten]

Hello!
I think this is the same as #2591
I do not have macOS, by any chance can you try with this file : https://github.com/WinkelCode/task/blob/e1d0a7e91ce1d5b8b19a9f4ee0a1b80c03043a18/completion/fish/task.fish ? (There is an ongoing PR)

[max-sixty]

that works great! TY!