[Bug] Builtin "which" prints errors to stdout instead of stderr

[Bug] Builtin "which" prints errors to stdout instead of stderr

[Laurent, Jean-Baptiste]

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Hi,

Zsh 5.3.1 error message < XXX not found > is printed to stdout instead of stderr.
Zsh 5.3.1 - 0 #> which ccache
ccache not found
Zsh 5.3.1 - 1 #> which ccache 2> /dev/null
Zsh 5.3.1 - 2 #> which which

This has been also tested with a fresh install of zsh (5.0.8)
Zsh 5.0.8 - 0 #> which ccache
/usr/bin/which: no ccache in (...)
Zsh 5.0.8 - 1 #> unalias which
Zsh 5.0.8 - 2 #> which which
which: shell built-in command
Zsh 5.0.8 - 3 #> which ccache
ccache not found
Zsh 5.0.8 - 4 #> which ccache 2> /dev/null
Zsh 5.0.8 - 5 #> which which

Re: [Bug] Builtin "which" prints errors to stdout instead of stderr

[Oliver Kiddle]

"Laurent, Jean-Baptiste" wrote:
>
> Zsh 5.3.1 error message < XXX not found > is printed to stdout instead of stderr.
> Zsh 5.3.1 - 0 #> which ccache
> ccache not found
> Zsh 5.3.1 - 1 #> which ccache 2> /dev/null
> Zsh 5.3.1 - 2 #> which which

I believe this is actually intentional for compatibility with csh. It is
arguably not an error but informational. This last came up in workers/38747.

The which external was traditionally a C-shell script. Still is on
Solaris. Recent Linux has it as a binary and does send it to stderr. On
FreeBSD, it is silent.

If this keeps coming up, perhaps it'd be easier just to change it.

Oliver