In the Ubuntu Error Tracker there was a crash report (https://errors.ubuntu.com/oops/70461390-2884-11e8-a005-fa163ed44aae) that was hanging the retracers. Looking at the ProcMaps file we can see the following:
7f19dbc5c000-7f19dbe06000 r-xp 00000000 08:02 665441 /tmp/syd-chroot/usr/lib/libc-2.27.so
7f19dbe06000-7f19dc006000 ---p 001aa000 08:02 665441 /tmp/syd-chroot/usr/lib/libc-2.27.so
7f19dc006000-7f19dc00a000 r--p 001aa000 08:02 665441 /tmp/syd-chroot/usr/lib/libc-2.27.so
7f19dc00a000-7f19dc00c000 rw-p 001ae000 08:02 665441 /tmp/syd-chroot/usr/lib/libc-2.27.so
The crash report was also from Ubuntu 17.10 which has libc version 2.26. gdb was hanging on this core file as there was a CRC mismatch for libc.
WARNING: /tmp/syd-chroot/usr/lib/libutil-2.27.so is needed, but cannot be mapped to a package
WARNING: /tmp/syd-chroot/usr/lib/libpthread-2.27.so is needed, but cannot be mapped to a package
WARNING: /tmp/syd-chroot/usr/lib/libc-2.27.so is needed, but cannot be mapped to a package
WARNING: /tmp/syd-chroot/usr/lib/libdl-2.27.so is needed, but cannot be mapped to a package
WARNING: /tmp/syd-chroot/usr/lib/libm-2.27.so is needed, but cannot be mapped to a package
...
warning: .dynamic section for "/mnt/sec-machines/apport-sandbox-dir/Ubuntu 17.10/amd64/report-sandbox/lib/x86_64-linux-gnu/libpthread-2.26.so" is not at the expected address (wrong library or version mismatch?)
warning: .dynamic section for "/mnt/sec-machines/apport-sandbox-dir/Ubuntu 17.10/amd64/report-sandbox/lib/x86_64-linux-gnu/libdl-2.26.so" is not at the expected address (wrong library or version mismatch?)
warning: .dynamic section for "/mnt/sec-machines/apport-sandbox-dir/Ubuntu 17.10/amd64/report-sandbox/lib/x86_64-linux-gnu/libutil-2.26.so" is not at the expected address (wrong library or version mismatch?)
warning: .dynamic section for "/mnt/sec-machines/apport-sandbox-dir/Ubuntu 17.10/amd64/report-sandbox/lib/x86_64-linux-gnu/libm-2.26.so" is not at the expected address (wrong library or version mismatch?)
Before a report is sent to the Error Tracker or Launchpad we should examine the ProcMaps file for libraries which will not be able to be mapped to a package i.e. ones that contain "/tmp" or "/run/schroot".
