(standalone) bitpack_test.o: No such file or directory (again)

To reproduce

Try to build standalone with LL_TESTS enabled, e.g.:

1. Get the fixes for OPEN-38 and OPEN-99

   hg clone https://bitbucket.org/boroondas/viewer-development-standalone -r f37dfe545aa8

2. cd viewer-development-standalone

3. If you use a distribution for which there isn't a package for the glh header:

   autobuild install glh_linear

   autobuild configure -c DebugOS -- -DSTANDALONE=ON -DWORD_SIZE=64 -DGLH_INCLUDE_DIR="$(pwd)/build-linux-i686/packages/include/"

   otherwise (if glh header is installed on your system) just:

   autobuild configure -c DebugOS -- -DSTANDALONE=ON -DWORD_SIZE=64

   (LL_TESTS defaults to ON, so we don't have to explicitly set it.)

4. Try to build (non-parallel, so we get better reproducibility):

   autobuild build -c DebugOS --no-configure -- -j1

Observed

[ 13%] Building CXX object llcharacter/CMakeFiles/llcharacter.dir/llvisualparam.o

Linking CXX static library libllcharacter.a

[ 13%] Built target llcharacter

Scanning dependencies of target INTEGRATION_TEST_bitpack

[ 13%] Building CXX object llcommon/CMakeFiles/INTEGRATION_TEST_bitpack.dir/tests/bitpack_test.o

c++: CMakeFiles/INTEGRATION_TEST_bitpack.dir/tests/bitpack_test.o: No such file or directory

make[2]: *** [llcommon/CMakeFiles/INTEGRATION_TEST_bitpack.dir/tests/bitpack_test.o] Error 1

make[1]: *** [llcommon/CMakeFiles/INTEGRATION_TEST_bitpack.dir/all] Error 2

make: *** [all] Error 2

ERROR: building default configuration returned 2

For more information: try re-running your command with --verbose or --debug

Regression

This did not happen in e67da2c6e312

Workaround

Skip building (and running) tests by configuring with -DLL_TESTS=OFF (after the --, as this option has to be passed through to CMake.)

Diagnosis

We had a similar issue in OPEN-39 (aka STORM-1132). As revealed by building with VERBOSE=1 (after the --, as this option has to be passed through to make), the direct cause is again a -I"" in the g++ call. As the fix for OPEN-39 seems to be present and intact, the root cause might be different.