OK, so let's please distinguish smaller problems and tackle them one at a time:
* packaging alire itself for Debian
I have raised a couple of issues in the Intent to Package bug[1]. It would be nice if
Alejandro and Stéphane could work together to solve them, I don't think there is anything
particularly difficult to do. If you want alire in the next stable release of Debian, this
must be done by the freeze date in less than a month[2], so please hurry, or wait another
2-3 years for the next stable release (of course, alire can reach unstable and testing much
earlier than that).
[1] https://urldefense.com/v3/__https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1029448__;!!D9dNQwwGXtA!X5xVtOX3rvxQoFrivq8ULuAuNrt85z1JnlnacHmsNKRU8CC_pTr3-PjHMduToZXbubiS4lbSmo-ILlmVX3xeaNQ$
[2] https://urldefense.com/v3/__https://release.debian.org/testing/freeze_policy.html__;!!D9dNQwwGXtA!X5xVtOX3rvxQoFrivq8ULuAuNrt85z1JnlnacHmsNKRU8CC_pTr3-PjHMduToZXbubiS4lbSmo-ILlmVY-BGgN8$
With this problem solved, it will become easier for users of Debian to use alire crates by
downloading and recompiling sources in their $HOME, as intended for a source package
manager.
* teach alire about the existing Debian packages
alire packaged for Debian should be able to discover existing binary packages like
libgtkada, libgnatcoll, xmlezout etc. so that any time a user uses /usr/bin/alr to download
and compile a crate, this automatically changes the source dependencies into external
(precompiled binary) dependencies. The goal would be to avoid recompiling gtkada etc. for
each crate.
Discovering existing packages is easy: per Debian Ada Policy, they must depend on the
package gnat. Therefore, any package that depends on gnat and whose name ends with -dev
should become an "external" dependency instead of a source dependency.
It is OK if this feature is optional but I would recommend opt-out, i.e. use installed
binary packages by default.
It is also OK if this ignores existing Debian packages that are not installed but perhaps
alire should warn about their existence and suggest the user install them.
* producing more Debian packages from alire crates
This is a longer-term goal. As I understand it, there should be a way to turn some source
dependencies into external dependencies, where a Debian package exists. Some improvements
in alire would be necessary but I don't think it is feasible to do that before the freeze.
Therefore, consider this a goal for the next stable release of Debian, which gives you ample
time.
--
Ludovic Brenta.