On 2018-02-05 13:25 -0500, Eli Schwartz wrote:
> Package: xvfb
> Version: 2:1.19.6-1
> Severity: minor
>
> Arch Linux has imported the xvfb-run script from Debian's package, but
> our package dependencies do not mandate that the "which" utility be
> installed. OTOH we do have it in our base package group, which users are
> expected to have installed, although there is a bit of bikeshedding
> about whether these unstated dependencies should actually be explicitly
> listed... See the following xvfb bugreport on our bugtracker:
> https://bugs.archlinux.org/task/56997
>
> All that being said, this immediately made me think, why is the script
> using `which` at all, rather than the POSIX `command -v` which is far
> more portable as any #!/bin/sh shell has this as a builtin.
Historical reasons, POSIX has only mandated "command -v" since 2008 and
Debian does not even require that /bin/sh supports it, since the Policy
Manual specifies SUSv3 aka POSIX.2001 as the baseline[1]. As a
consequence, the minimal posh shell does not support[2] "command -v"
(not that using posh as /bin/sh is actually supported in Debian).
See also bugs #747320[3] (talks about the "type" command, but mentions
"command -v" in the last comment) and #864615[4] (requests that Debian
should upgrade to SUSv4).
Cheers,
Sven
1. https://www.debian.org/doc/debian-policy/#scripts
2. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=397601
3. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=747320
4. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=864615
