Provide list of chroots (--list-chroots) in machine-readable format

[scfc]

I'm working on polishing up an Emacs TRAMP method for editing within Mock. To provide completion of possible chroots, I need to have a list of them.

mock -q --list-chroots does not look stable in that regard (generated by mock/py/mockbuild/config.py):

$ mock -q --list-chroots
config name                        description
Global configs:
alma+epel-8-aarch64                AlmaLinux 8 + EPEL
alma+epel-8-ppc64le                AlmaLinux 8 + EPEL
alma+epel-8-x86_64                 AlmaLinux 8 + EPEL
[…]
$

It has a row with the column names (suggesting the columns may change) and interjects "Global configs:" and sometimes "Custom configs:" into the table.

Not so surprisingly, mock/etc/bash_completion.d/mock therefore duplicates the code to list the chroots (in shell script).

It would be nice if Mock provided an option to list chroots in a machine-readable format (and probably then used that in mock/etc/bash_completion.d/mock). The output should consist (only) of the list (implying -q), no headers and no interlines, with each line consisting only of the name of the chroot as it can be passed to mock -r.

[praiskup]

Thank you for the report. Bash-completion just needs to have a list of files, while --list-chroots parses those files too, to print out additional metadata.

Said that I can imagine having a --list-chroots-config-files printing just filenames - and start using that option even in Mock's bash completion. Or using --list-chroots --only-filenames. Or something like that. Patches are welcome.