SConstruct : Race condition when building Cortex in debug mode (linking IECorePython when it isn't ready yet)

[boberfly]

Version: Cortex 10.4.2.1 + #1307

Description

This bug has reared up again and now with 1 thread or more for me consistently: #1185
Still a race condition of sorts but consistent with GCC 11 when building Cortex in debug mode (probably takes a lot longer to output the library and SCons tries to invoke the linker too soon?).

Steps to Reproduce

1. Build Cortex from gafferDependencies with 1 or more jobs with BUILD_TYPE=DEBUG

Debug Log

Click to Expand

/bin/ld: error: /home/alex/dev/dependencies/rl9/lib/libIECorePython.so: file too short