${variant:targetVariant} is not expanded properly since v1.5

[ghost]

Brief Issue Summary

The following configuration (expansion) does not work anymore since v1.5
"cmake.buildDirectory": "${workspaceFolder}/build/${variant:targetVariant}/${buildKit}"

Expected:

1. Configuration in settings.json:

"cmake.buildDirectory": "${workspaceFolder}/build/${variant:targetVariant}/${buildKit}"

[cmake] Not searching for unused variables given on the command line.
[cmake] CMake Error at /usr/local/lib/python3.6/dist-packages/cmake/data/share/cmake-3.18/Modules/CTestTargets.cmake:59 (add_custom_target):
[cmake]   Syntax error in cmake code when parsing string
[cmake] 
[cmake]     /workspace/build/${variant:targetVariant}/X86/CMakeFiles/Experimental
[cmake] 
[cmake]   Invalid character (':') in a variable name: 'variant'

and

targetVariant:
    default: 'Test1'
    choices:
        'Test1':
            short: 'Test1'
            long: 'Test1'
            settings:
                PROJECT: "Test1"
                DEBUG_ASSERT: "false"
        'Test2':
            short: 'Test2'
            long: 'Test2'
            settings:
                PROJECT: "Test2"
                DEBUG_ASSERT: "true"
buildType:
    default: Debug
    choices:
        Debug:
            short: Debug
            long: Debug
            buildType: Debug

2. Configuration succeeds.

Apparent Behavior:

Configuration does not work.
${buildKit} is still correctly expanded, the variant unfortunately not.

CMake Tools Log

[main] Configuring folder: workspace 
[driver] Removing /workspace/build/${variant:targetVariant}/X86/CMakeCache.txt
[driver] Removing /workspace/build/${variant:targetVariant}/X86/CMakeFiles
[proc] Executing command: /usr/local/bin/cmake --no-warn-unused-cli -DPROJECT:STRING=Test1 -DDEBUG_ASSERT:STRING=false -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=TRUE -DCMAKE_BUILD_TYPE:STRING=Debug -DCMAKE_TOOLCHAIN_FILE:FILEPATH=/workspace/Configuration/Unittest.cmake -H/workspace -B/workspace/build/${variant:targetVariant}/X86 -G Ninja
[cmake] Not searching for unused variables given on the command line.
[cmake] CMake Error at /usr/local/lib/python3.6/dist-packages/cmake/data/share/cmake-3.18/Modules/CTestTargets.cmake:59 (add_custom_target):
[cmake]   Syntax error in cmake code when parsing string
[cmake] 
[cmake]     /workspace/build/${variant:targetVariant}/X86/CMakeFiles/Experimental
[cmake] 
[cmake]   Invalid character (':') in a variable name: 'variant'
[cmake] Call Stack (most recent call first):
[cmake]   /usr/local/lib/python3.6/dist-packages/cmake/data/share/cmake-3.18/Modules/CTest.cmake:266 (include)
[cmake]   Configuration/Unittest.cmake:19 (include)
[cmake]   /usr/local/lib/python3.6/dist-packages/cmake/data/share/cmake-3.18/Modules/CMakeDetermineSystem.cmake:93 (include)
[cmake]   CMakeLists.txt:8 (project)
[cmake] 
[cmake] 
[cmake] CMake Error: CMake was unable to find a build program corresponding to "Ninja".  CMAKE_MAKE_PROGRAM is not set.  You probably need to select a different build tool.
[cmake] CMake Error: CMAKE_C_COMPILER not set, after EnableLanguage
[cmake] CMake Error: CMAKE_CXX_COMPILER not set, after EnableLanguage
[cmake] -- Configuring incomplete, errors occurred!

Platform and Versions

• Operating System: Docker inside WSL2 using ubuntu 18.04 LTS
• CMake version:3.18.2
• VsCode Version:1.50.1
• CMake Tools Extension Version: V1.5
• Compiler:gcc (Ubuntu 9.3.0-11ubuntu0~18.04.1) 9.3.0

Other Notes/Information

This issue arises with the new version v1.5. Previous versions still work (since at least 05/2019).

[bobbrow]

Thank you for reporting this issue. We will investigate and try to get a patch out soon.