Code review comment for lp:~alan-griffiths/mir/fix-FTBFS

$ make -j5 miral-test
[...]
[100%] Linking CXX executable ../../bin/miral-test.bin

Before (on zesty):
lto1: internal compiler error: in add_symbol_to_partition_1, at lto/lto-partition.c:135
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-6/README.Bugs> for instructions.
lto-wrapper: fatal error: /usr/bin/c++ returned 1 exit status
compilation terminated.
/usr/bin/ld: error: lto-wrapper failed
collect2: error: ld returned 1 exit status

After:
[100%] Built target miral-test