Questions[source-packages](ubuntu)

We can find the source of the package with apt show <package name>, but how do we find the list of all binaries or packages a source provides?

For example apt show will give following information and more

$ apt show linux-libc-dev
Package: linux-libc-dev
Version: 4.4.0-96.119
Priority: optional
Section: devel
Source: linux
Origin: Ubuntu

Here the source is "linux". Similarly, I remember using a command to get all the packages from the source "linux", which gives all the binaries and packages.

I've got some crash files for recoll from which I would like to extract a symbolic stack trace. Unfortunately, there are no debug symbols available for this package, so my stack traces are mostly unhelpful.

The crash files are generated by apport for /usr/bin/recoll, so I want to use symbols from an external file rather than compiling from source with debugging symbols (because then I'd have to reproduce the crash). Based on the build ID, I'd expect them to go under /usr/lib/debug/.build-id/7e/83e15f5cfae88cef2850e4a510f4d4849ae6b9.debug:

$ file /usr/bin/recoll
/usr/bin/recoll: ELF 64-bit LSB shared object, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/l, for GNU/Linux 3.2.0, BuildID[sha1]=7e83e15f5cfae88cef2850e4a510f4d4849ae6b9, stripped
$ gdb
(gdb) show debug-file-directory
The directory where separate debug symbols are searched for is "/usr/lib/debug".

I know I could add to the debug-file-directory, something like this:

(gdb) set debug-file-directory /usr/lib/debug:/home/nathaniel/mysymbols

but I still need to compile the object file, and I'm having trouble finding sufficient documentation on how to do this with apt/dpkg. Sure, I can use apt-get source -b recoll to download and build it, but the build ID isn't the same and the final executable is still stripped. I'm guessing this is because -fdebug-prefix-map isn't the same.

$ sudo apt-get build-dep recoll
$ apt-get source -b recoll
<snip>
./configure CFLAGS="-g -O2 -fdebug-prefix-map=/home/nathaniel/apt-get-source/recoll/recoll-1.23.7=.
<snip>
$ file recoll-1.23.7/qtgui/recoll
recoll-1.23.7/qtgui/recoll: ELF 64-bit LSB shared object, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/l, for GNU/Linux 3.2.0, BuildID[sha1]=be2479236c840a60c71848f9d8257b68856f28f5, not stripped
$ file recoll-1.23.7/debian/recoll/usr/bin/recoll
recoll-1.23.7/debian/recoll/usr/bin/recoll: ELF 64-bit LSB shared object, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/l, for GNU/Linux 3.2.0, BuildID[sha1]=be2479236c840a60c71848f9d8257b68856f28f5, stripped

so my question is:

How can I manually compile and install the debugging symbols for the recoll package on Ubuntu 18.04?

Related:

• Where are the debug symbols for plasmashell (Kubuntu 19.04)?
• OpenJDK - Installing JDK Debug Symbols manually
• https://randomascii.wordpress.com/2013/02/20/symbols-on-linux-part-three-linux-versus-windows/
• https://stackoverflow.com/questions/14473506/gdb-core-dump-find-executable-by-build-id
• https://stackoverflow.com/questions/28787534/debug-information-file-conventions-for-debian-ubuntu

Given this /etc/apt/sources.list file:

deb     http://us.archive.ubuntu.com/ubuntu/ cosmic main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ cosmic main restricted universe multiverse
deb     http://us.archive.ubuntu.com/ubuntu/ disco  main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ disco  main restricted universe multiverse

and this /etc/apt/preferences file:

Package: *
Pin: release a=cosmic
Pin-Priority: 900

Package: *
Pin: release a=disco
Pin-Priority: -10

Running apt install some-package will install the version from cosmic, as I'd expect.

However, running apt source some-package will download the (newer) version from disco.

How can I make apt source obey pin-priorities?

The Debian package directory provides a simple API to search for package releases. For instance this query results can be accessed as JSON at https://sources.debian.net/api/src/libtry-tiny-perl/. Is there a similar API for http://packages.ubuntu.com/?

Currently my program installs to /usr/bin or whatever and I need to change it to /opt/appname. Where do I specify that in the debian source package?

Rasmus