[Windows] ROOT 6.38 + Python 3.14: No module named 'libcppyy' [CEA 52284]

ROOT
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4

Thank you very much for your workaround solution.

Here is the previous test:

PS C:\Users\...\downloads> Get-Date

mercredi 15 avril 2026 13:55:57


PS C:\Users\...\downloads> . .\root_v6.38.04.win64.python314.vc18.relwithdebinfo\root\bin\thisroot.ps1
PS C:\Users\...\downloads> py -3.14 -c "import ROOT"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
    import ROOT
  File "C:\Users\...\downloads\root_v6.38.04.win64.python314.vc18.relwithdebinfo\root\bin\ROOT\__init__.py", line 21, in <module>
    import cppyy
  File "C:\Users\...\downloads\root_v6.38.04.win64.python314.vc18.relwithdebinfo\root\bin\cppyy\__init__.py", line 74, in <module>
    from ._cpython_cppyy import *
  File "C:\Users\...\downloads\root_v6.38.04.win64.python314.vc18.relwithdebinfo\root\bin\cppyy\_cpython_cppyy.py", line 24, in <module>
    import libcppyy as _backend
ModuleNotFoundError: No module named 'libcppyy'
PS C:\Users\...\downloads>

After copying the dynamic library, import ROOT succeeded:

PS C:\Users\...\downloads> cp ${ROOTSYS}\bin\cppyy\libcppyy.pyd ${ROOTSYS}\bin
PS C:\Users\...\downloads> py -3.14 -c "import ROOT"
PS C:\Users\...\downloads>

Best regards,

1 Like