debian-grab-sources-at-same-version-as-installed-debug-packages

# Downloads and unpacks (in subdirs of the current directory) all of the
# Debian source packages associated with the *-dbgsym and *-dbg packages whose
# symbols are referenced by the specified program ('/usr/bin/someprogram' in
# the snippet below). Takes pains to ensure the downloaded source packages are
# at the exact same version number as the corresponding *-dbgsym/*-dbg
# packages.
#
# Assumes you are in the directory beneath which you would like the sources to
# be unpacked (by 'apt-get source'). Each unique package will have a separate
# subdirectory. We are not clever about avoiding duplicates, but 'apt-get source'
# already is.
#
# Motivation:
# -----------
# Helps prepare for a gdb(1) debugging session for a given program (assuming
# that program was installed by the Debian packaging system). Easier than
# manually tracking down all dependencies manually. For such work, you need
# the debug symbols for all dependencies (provided in the *-dbgsym or *-dbg
# packages) and also the source code (the part fetched by this gist).
#
# For the most part, gdb(1) will automatically find the debug symbols from the
# installed *-dbgsym and *-dbg packages, but you will need to use one or more
# gdb 'directory' commands to tell it where the source code lives (for use by
# the gdb 'list' command, and similar).
#
# Background context:
# -------------------
# The 'find-dbgsym-packages(1)' program comes from the 'debian-goodies' Debian
# package, but its default behavior (as provided by debian-goodies-0.84) is to
# only print the names of *-dbgsym and *-dbg packages that are not already
# installed. Internally, it is using the `eu-unstrip' program (provided by the
# 'elfutils' package) to decide whether or not to print the *-dbgsym/*-dbg
# package name for a given dependency by parsing the output of this
# invocation:
#
#     eu-unstrip --list-only --executable
#
# The 'find-dbgsym-package' program explicitly filters out the names of the
# packages when it detects their associated debug symbols are already present.
#
# This gist uses a quick 'n dirty modified version that does not do that
# filtering out:
#
#     $ diff tt/find-dbgsym-packages tt/find-dbgsym-packages-ALJUNK-HACKED-TO-NOT-IGNORE-ALREADY-INSTALLED-DBGSYM-PACKAGES 
#     116,118c116,118
#     <             if ($debug ne '-') {
#     <                 next;
#     <             }
#     ---
#     > #            if ($debug ne '-') {
#     > #                next;
#     > #            }
#

# Single line, for easier copy/pasting:
#
$ ./tt/find-dbgsym-packages-ALJUNK-HACKED-TO-NOT-IGNORE-ALREADY-INSTALLED-DBGSYM-PACKAGES /usr/bin/someprogram | tr ' ' '\n' | while read -r pkg_dbgsym; do pkg_raw=$(echo "${pkg_dbgsym}" | sed -e 's/^\(.\{1,\}\)[-]\(dbg\|dbgsym\)$/\1/'); echo $pkg_raw; done | while read -r pkg; do iver=$(dpkg-query --show --showformat '${Version}' "${pkg}"); ( set -x;  test -d "./${pkg}-${iver}" || apt-get source ${pkg}=${iver} && sleep 2); done


# Multiple lines, for better readability here:
#
$ ./tt/find-dbgsym-packages-ALJUNK-HACKED-TO-NOT-IGNORE-ALREADY-INSTALLED-DBGSYM-PACKAGES /usr/bin/someprogram \
>     | tr ' ' '\n' \
>     | while read -r pkg_dbgsym; do
>           pkg_raw=$(echo "${pkg_dbgsym}" \
>                     | sed -e 's/^\(.\{1,\}\)[-]\(dbg\|dbgsym\)$/\1/' \
>                    );\
>           echo $pkg_raw ;\
>       done \
>     | while read -r pkg; do
>           iver=$(dpkg-query --show --showformat '${Version}' "${pkg}");
>           ( set -x; \
>             test -d "./${pkg}-${iver}" || apt-get source ${pkg}=${iver} && sleep 2
>           );\
>       done