Bug#918121: libgazebo9-dev: gazebo.pc has broken link flags

[Emilio Pozuelo Monfort]

Package: libgazebo9-dev
Version: 9.4.1+dfsg-1
Severity: serious

Hi,

libgazebo9-dev 9.4.1+dfsg-1+b2 (rebuilt for the gdal transition, though this
breakage may or may not be related to gdal) ships a broken gazebo.pc:

Libs: -Wl,-rpath,${prefix}/lib/x86_64-linux-gnu/gazebo-9/plugins -L${libdir} -L${prefix}/lib/x86_64-linux-gnu/gazebo-9/plugins -lgazebo_transport -lgazebo_physics -lgazebo_sensors -lgazebo_rendering -lgazebo_gui -lgazebo_client -lgazebo_msgs -lgazebo_common -lgazebo -L/usr/lib/x86_64-linux-gnu -lboost_thread -l-lpthread -lboost_signals -lboost_system -lboost_filesystem -lboost_program_options -lboost_regex -lboost_iostreams -lboost_date_time -lboost_chrono -lboost_atomic 

Observe the flag -l-lpthread, which is bogus, and may be the result of two
different flags, with the first one containing an empty substitution.

This causes the autopkgtest failure found in:

https://ci.debian.net/data/autopkgtest/testing/amd64/g/gazebo/1633147/log.gz
https://ci.debian.net/packages/g/gazebo/testing/amd64/

Which is triggered by gdal update only because that causes the gazebo/sid
package to be installed, which fails. However this may be the result of
another package, more investigation is needed.

Cheers,
Emilio