Bug 1517259

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.