We cannot rely on wrapPythonPrograms to wrap the installed executables because
they are symlinks (which it ignores). Instead, we have to emulate it to make
the wrappers ourselves.
Additional CUPS drivers can be added via "services.printing.drivers" but
Gutenprint was an exception. It was possible to add a Gutenprint
derivation to that list and it would work at first but unlike the other
drivers Gutenprint requires a script to be run after each update or any
attempt to print something would simply fail and an error would show up
in the jobs queue (http://localhost:631/jobs/):
"The PPD version (5.2.11) is not compatible with Gutenprint 5.2.13.
Please run
`/nix/store/7762kpyhfkcgmr3q81v1bbyy0bjhym80-gutenprint-5.2.13/sbin/cups-genppdupdate'
as administrator."
This is due to state in "/var/lib/cups/ppd" and one would need to run
"/nix/store/.../bin/cups-genppdupdate -p /var/lib/cups/ppd" manually.
The alternative was to enable the following option:
"services.printing.gutenprint" but this had two disadvantages:
1) It is an exception that one could be unaware of or that could
potentially cause some confusion.
2) One couldn't use a customized Gutenprint derivation in
"services.printing.drivers" but would instead have to overwrite
"pkgs.gutenprint".
This new approach simply detects a Gutenprint derivation in
"services.printing.gutenprint" by checking if the meta set of a
derivation contains "isGutenprint = true". Therefore no special
exception for Gutenprint would be required and it could easily be
applied to other drivers if they would require such a script to be run.
* pkgs: refactor needless quoting of homepage meta attribute
A lot of packages are needlessly quoting the homepage meta attribute
(about 1400, 22%), this commit refactors all of those instances.
* pkgs: Fixing some links that were wrongfully unquoted in the previous
commit
* Fixed some instances
* hplip: introduce nettools dependency
Some HP printers (notably a HP MFP M477fnw) need to run `hostname` as part of
the printing process. This executable is provided by the "nettools" package.
* hplip: prepend nettools to PATH
