It's actually unavailable in the minimal chroots Debian builds our
package on. That's allowed by POSIX, which specifies ps(1) to be
optional, whereas id(1) —
- is not optional in POSIX
- should exist on every system anyone might run the testsuite on
- has the same length name, so test expectations don't have to be updated
- doesn't take a filename argument (ditto)
That does make the pipeline as a whole somewhat nonsensical
semantically, but it remains just as valid syntactically.
All these files should be sourced, not executed; and Debian's lintian complains:
W: zsh-syntax-highlighting: script-not-executable usr/share/zsh-syntax-highlighting/zsh-syntax-highlighting.zsh
* Don't override user defined styles
* Better modularisation of highlighters
* Allow to define which highlighters are activated
* Allow to define the order in which they are defined
* Minor performance optimizations
* Fixed some variables leak
* Improve documentation
* Brackets highlighter: use ZSH_HIGHLIGHT_STYLES instead of a specific array