# Linux — Building and Debugging GTK Sometimes installing the debug packages for gtk and glib isn't quite enough. (For instance, if the artifacts from -O2 are driving you bonkers in gdb, you might want to rebuild with -O0.) Here's how to build from source and use your local version without installing it. [TOC] ## 32-bit systems On Ubuntu, to download and build glib and gtk suitable for debugging: 1. If you don't have a gpg key yet, generate one with `gpg --gen-key`. 2. Create file `~/.devscripts` containing `DEBSIGN_KEYID=yourkey`, e.g. `DEBSIGN_KEYID=CC91A262` (See http://www.debian.org/doc/maint-guide/ch-build.en.html) 3. If you're on a 32 bit system, do: ```shell #!/bin/sh set -x set -e # Workaround for "E: Build-dependencies for glib2.0 could not be satisfied" # See also https://bugs.launchpad.net/ubuntu/+source/apt/+bug/245068 sudo apt-get install libgamin-dev sudo apt-get build-dep glib2.0 gtk+2.0 rm -rf ~/mylibs mkdir ~/mylibs cd ~/mylibs apt-get source glib2.0 gtk+2.0 cd glib2.0* DEB_BUILD_OPTIONS="nostrip noopt debug" debuild cd ../gtk+2.0* DEB_BUILD_OPTIONS="nostrip noopt debug" debuild ``` This should take about an hour. If it gets stuck waiting for a zombie, you may have to kill its closest parent (the makefile uses subshells, and bash seems to get confused). When I did this, it continued successfully. At the very end, it will prompt you for the passphrase for your gpg key. Then, to run an app with those libraries, do e.g. export LD_LIBRARY_PATH=$HOME/mylibs/gtk+2.0-2.16.1/debian/install/shared/usr/lib:$HOME/mylibs/gtk+2.0-2.20.1/debian/install/shared/usr/lib gdb ignores that variable, so in the debugger, you would have to do something like set solib-search-path $HOME/mylibs/gtk+2.0-2.16.1/debian/install/shared/usr/lib:$HOME/mylibs/gtk+2.0-2.20.1/debian/install/shared/usr/lib See also http://sources.redhat.com/gdb/current/onlinedocs/gdb_17.html ## 64-bit systems If you're on a 64 bit system, you can do the above on a 32 bit system, and copy the result. Or try one of the following: ### Building your own GTK ```shell apt-get source glib-2.0 gtk+-2.0 export CFLAGS='-m32 -g' export LDFLAGS=-L/usr/lib32 export LD_LIBRARY_PATH=/work/32/lib export PKG_CONFIG_PATH=/work/32/lib/pkgconfig # glib setarch i386 ./configure --prefix=/work/32 --enable-debug=yes # gtk setarch i386 ./configure --prefix=/work/32 --enable-debug=yes --without-libtiff ``` ### ia32-libs _Note: Evan tried this and didn't get any debug libs at the end._ Or you could try this instead: ``` #!/bin/sh set -x set -e sudo apt-get build-dep ia32-libs rm -rf ~/mylibs mkdir ~/mylibs cd ~/mylibs apt-get source ia32-libs cd ia32-libs* DEB_BUILD_OPTIONS="nostrip noopt debug" debuild ``` By default, this just grabs and unpacks prebuilt libraries; see ia32-libs-2.7ubuntu6/fetch-and-build which documents a BUILD variable which would force actual building. This would take way longer, since it builds dozens of libraries. I haven't tried it yet. #### Possible Issues debuild may fail with ``` gpg: [stdin]: clearsign failed: secret key not available debsign: gpg error occurred! Aborting.... ``` if you forget to create `~/.devscripts` with the right contents. The build may fail with a `FAIL: abicheck.sh` if gold is your system linker. Use ld instead.