Created attachment 1358646 [details] Test program with a error detected by ubsan Description of problem: The debug symbols for the ubsan and asan runtime libraries cannot be obtained by any obvious means anymore in Fedora 27. Version-Release number of selected component (if applicable): gcc 7.2.1.2.fc27 (other packages involved: libubsan 7.2.1 2.fc27 and libasan 7.2.1.2.fc27) How reproducible: Always reproducible. Tried on two machines upgraded for Fedora 26, and it occurred on both. Steps to Reproduce: 1. Compile attached ubsan-crash.cc with ubsan: $ g++ -fsanitize=undefined -g ubsan-crash.cc 2. Launch gdb with the result: $ gdb a.out 3. Run the program in gdb (gdb) run 4. Run the command gdb suggests to install libubsan.so.0's debug symbols 5. Try to get a backtrace from gdb (gdb) bt 6. Try to see the source where the crash occurred (gdb) tui enable 7. Try setting a breakpoint on __ubsan::ScopedReport::~ScopedReport (gdb) break __ubsan::ScopedReport::~ScopedReport Actual results: The command given by gdb to install the debug info fails: > $ sudo dnf --enablerepo='*debug*' install /usr/lib/debug/.build-id/43/cc661ae0597e577f445abdc575571905955dcd.debug > No match for argument: /usr/lib/debug/.build-id/43/cc661ae0597e577f445abdc575571905955dcd.debug > Error: Unable to find a match The backtrace has ?? for some symbol names, and the source is missing for anything in libubsan.so.0. The symbol __ubsan::ScopedReport::~ScopedReport is not found. Expected results: The command for installing the debug symbols installs a package. When restarting gdb and trying again, the backtrace will have function names and the source can be viewed. Setting a breakpoint on __ubsan::ScopedReport::~ScopedReport finds the function and sets a breakpoint there. When upgrading from Fedora 26 where the appropriate debug package was already installed, gdb just finds the debug symbols the first time and doesn't even ask for a debuginfo package to be installed. Additional info: This is a regression from Fedora 26, where the debug information was available. You could set breakpoints on symbols such as __asan::ReportGenericError and __ubsan::ScopedReport::~ScopedReport and see the source for them in gdb and a full backtrace when errors were detected. The command $ sudo dnf debuginfo-install libubsan libasan will install gcc-debuginfo-7.2.1-2.fc27.x86_64, but this does not help. (libubsan being the name of the package that provides /usr/lib64/libubsan.so.0.) There is no package gcc-debugsource available.
Surely installing gcc-debuginfo doesn't help? It's got /usr/lib/debug/usr/lib/gcc/x86_64-redhat-linux/7/libubsan.a /usr/lib/debug/usr/lib64/libubsan.so.0.0.0.debug /usr/lib/debug/usr/lib64/libubsan.so.0.debug /usr/lib/debug/usr/lib64/libubsan.so.debug etc.
(In reply to Marek Polacek from comment #1) > Surely installing gcc-debuginfo doesn't help? On my machines, rpm -ql gcc-debuginfo produces: /usr/lib/debug /usr/lib/debug/.dwz /usr/lib/debug/.dwz/gcc-7.2.1-2.fc27.x86_64 I tried reinstalling it, but nothing changed. I can't find any package containing those files with dnf provides --enablerepo fedora-debuginfo --enablerepo updates-debuginfo.
gcc-7.3.1-2.fc27 has been submitted as an update to Fedora 27. https://bodhi.fedoraproject.org/updates/FEDORA-2018-75d88970d0
gcc-7.3.1-2.fc26 has been submitted as an update to Fedora 26. https://bodhi.fedoraproject.org/updates/FEDORA-2018-aa879be08e
gcc-7.3.1-2.fc26 has been pushed to the Fedora 26 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2018-aa879be08e
gcc-7.3.1-2.fc27 has been pushed to the Fedora 27 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2018-75d88970d0
gcc-7.3.1-2.fc26 has been pushed to the Fedora 26 stable repository. If problems still persist, please make note of it in this bug report.
gcc-7.3.1-2.fc27 has been pushed to the Fedora 27 stable repository. If problems still persist, please make note of it in this bug report.