Starting build on ROOT-performance-centos8-multicore/soversion, ROOT-ubuntu2204/nortcxxmod, ROOT-ubuntu2004/python3, mac11/noimt, mac12arm/cxx20, windows10/default
How to customize builds

Well, I'm trying this solution:

    set(CMAKE_SOURCE_DIR_ESCAPED ${CMAKE_SOURCE_DIR})
    set(CMAKE_BINARY_DIR_ESCAPED ${CMAKE_BINARY_DIR})
    set(special_chars [ ] + ( ))
    foreach(char ${special_chars})
       string(REPLACE ${char} "\\${char}" CMAKE_SOURCE_DIR_ESCAPED ${CMAKE_SOURCE_DIR_ESCAPED})
       string(REPLACE ${char} "\\${char}" CMAKE_BINARY_DIR_ESCAPED ${CMAKE_BINARY_DIR_ESCAPED})
    endforeach()

    list(FILTER incdirs EXCLUDE REGEX "^${CMAKE_SOURCE_DIR_ESCAPED}")
    list(FILTER incdirs EXCLUDE REGEX "^${CMAKE_BINARY_DIR_ESCAPED}/ginclude")
    list(FILTER incdirs EXCLUDE REGEX "^${CMAKE_BINARY_DIR_ESCAPED}/externals")
    list(FILTER incdirs EXCLUDE REGEX "^${CMAKE_BINARY_DIR_ESCAPED}/builtins")

(but note my comment on #13731), I think we can only escape the + without having to change the way ${ROOTSYS} is used

Test Results

         9 files           9 suites   2d 6h 4m 2s ⏱️
  2 489 tests   2 482 ✔️ 0 💤 7 ❌
21 450 runs  21 443 ✔️ 0 💤 7 ❌

For more details on these failures, see this check.

Results for commit c591b09.

Closing this PR as we understood that there is no proper way to treat special characters in build directories in cmake. Possibly, a different PR with a patch to throw an error if special characters are used will be open