SCons / test / MSVC /

The default branch has multiple heads

Author Commit Message Date Builds
- moved check for an installed MSVC toolchain into its own function in TestSCons
- fixes for MinGW under Windows, mainly skipping MSVS-specific tests
Steven Knight
Issue 2505: fix use of pre-compiled headers when the source .cpp file is listed in both the env.PCH() and env.Program() calls.