Compiler + Xcode 10.1 Error

[livemath]

When I install the older compilers for Xcode 10.1 on High Sierra I get the following error at (any) compile:

: could not create session: requestError(description: "unknown error
: while handling message: unableToInitializeCore(errors:
: ["/Applications/Xcode.app/Contents/PlugIns/Xcode3Core.ideplugin/
: Contents/SharedSupport/Developer/Library/Xcode/Plug-ins/GCC
: 4.0.xcplugin/Contents/Resources/GCC Generic.xcspec: warning: spec
: \':com.apple.compilers.gcc\' already registered from
: /Applications/Xcode.app/Contents/PlugIns/Xcode3Core.ideplugin/Contents
: /SharedSupport/Developer/Library/Xcode/Plug-ins/Clang LLVM
: 1.0.xcplugin/Contents/Resources/Default Compiler.xcspec",
: "/Applications/Xcode.app/Contents/PlugIns/Xcode3Core.ideplugin/
: Contents/SharedSupport/Developer/Library/Xcode/Plug-ins/GCC
: 4.2.xcplugin/Contents/Resources/GCC 4.2.xcspec: error: unknown spec
: \'Class\': \'PBXCompilerSpecificationGcc3_3\'",
: "/Applications/Xcode.app/Contents/PlugIns/Xcode3Core.ideplugin/
: Contents/SharedSupport/Developer/Library/Xcode/Plug-ins/GCC
: 4.0.xcplugin/Contents/Resources/GCC 4.0.xcspec: error: unknown spec
: \'Class\': \'PBXCompilerSpecificationGcc3_3\'"])")

[ShikiSuen]

I have met exactly the same problem.

[ShikiSuen]

[a2sheppy]

Same issue here. I spent a little time trying to figure it out and came up with very little, other than wondering if perhaps the new build system in Xcode 10.1 is a factor.

[gghose]

Yes, switch to the old build system, and things should work.