Automatically download missing dynamic lib debug symbols in gdb and debian

by epilys on 2023-03-20

🔗TL;DR

Set export DEBUGINFOD_URLS="https://debuginfod.debian.net" to automatically download missing debug symbols in gdb.

Found this in the Debian wiki: You can configure gdb, elfutils and binutils to automatically download debug symbols from debian’s official debuginfod server. This can save you time by not needing to separately download debug symbol packages.

🔗Configuration

Set the environment variable $DEBUGINFOD_URLS:

export DEBUGINFOD_URLS="https://debuginfod.debian.net"

And whenever you launch gdb etc with missing debug symbols in libraries, it will query the server for debug symbols. On gdb startup, you should see lines like Downloading separate debug info for /lib/x86_64-linux-gnu/liblz4.so.1... for each dynamically linked library. Beware that this can cause a large number of symbols to be downloaded if the transitive linked dependencies are too many.

You can check approximately how many separate symbol packages it would download in a fresh run for a specific binary by using ldd to list dependencies:

$ ldd a.out

You can also set the server URL in your .gdbinit configuration instead. Example values taken from the GDB online documentation:

set debuginfod enabled on
#set debuginfod enabled off
#set debuginfod enabled ask

# space separated URL list
set debuginfod urls https://debuginfod.debian.net

# inspect settings:
#show debuginfod enabled
#show debuginfod urls

Location of the symbol cache is:

• if DEBUGINFOD_CACHE_PATH is set, then the files are saved in the directory pointed by it.
• Otherwise, if XDG_CACHE_HOME is set, then files are saved into $XDG_CACHE_HOME/debuginfod_client.
• Otherwise, the files will be saved into $HOME/.cache/debuginfod_client.

Can I delete the cache directory? Yes.