Getting this error fairly reliably when trying to step through a program (test-unlock-keyring from gnome-keyring source) with gdb on f21 (gdb-7.8-25.fc21.x86_64). This looks similar to https://sourceware.org/bugzilla/show_bug.cgi?id=17408
gdb-7.8.1-30.fc21 has been submitted as an update for Fedora 21. https://admin.fedoraproject.org/updates/gdb-7.8.1-30.fc21
Package gdb-7.8.1-30.fc21: * should fix your issue, * was pushed to the Fedora 21 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing gdb-7.8.1-30.fc21' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2014-13913/gdb-7.8.1-30.fc21 then log in and leave karma (feedback).
gdb-7.8.1-30.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.
I'm hitting this on Fedora 21 with gdb-7.8.2-38.fc21.x86_64 and binutils-2.24-30.fc21.x86_64 when debugging with insight-7.8.50-4.20140827git.fc21.x86_64. Maybe it's because insight is "older" than the fix? The failed assertion doesn't seem to happen in commandline gdb.
'insight' contains its own build of GDB so file that for Component 'insight'.