v3.1.2

• Fix build when CMAKE_OSX_SYSROOT is not defined (10040)
• Fix build when make gen is called after make clobber (a632e)
• Bump minimum cmake version to 3.12.0 (42d35)
• Regenerate error code mappings for recent macOS (f2baa)
• Minor fixes in cmake and scripts
• Minor improvements in CI