./singleheader/amalgamate.py --with-utf8

SCRIPTPATH=.../simdutf/singleheader PROJECTPATH=.../simdutf
We are about to amalgamate all simdutf files into one source file.
See https://www.sqlite.org/amalgamation.html and https://en.wikipedia.org/wiki/Single_Compilation_Unit for rationale.
timestamp is 2025-02-17 16:38:44 +0100
Creating .../simdutf/singleheader/simdutf.h
Traceback (most recent call last):
  File ".../simdutf/./singleheader/amalgamate.py", line 488, in <module>
    main()
    ~~~~^^
  File ".../simdutf/./singleheader/amalgamate.py", line 49, in main
    create_files()
    ~~~~~~~~~~~~^^
  File ".../simdutf/./singleheader/amalgamate.py", line 276, in create_files
    doinclude(header, f"ERROR {header} not found")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../simdutf/./singleheader/amalgamate.py", line 177, in doinclude
    dofile(directory, file)
    ~~~~~~^^^^^^^^^^^^^^^^^
  File ".../simdutf/./singleheader/amalgamate.py", line 209, in dofile
    doinclude(includedfile, line)
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File ".../simdutf/./singleheader/amalgamate.py", line 177, in doinclude
    dofile(directory, file)
    ~~~~~~^^^^^^^^^^^^^^^^^
  File ".../simdutf/./singleheader/amalgamate.py", line 197, in dofile
    for line in context.read_file(file):
                ~~~~~~~~~~~~~~~~~^^^^^^
  File ".../simdutf/./singleheader/amalgamate.py", line 354, in filter_features
    raise ValueError(f"{file}:{lineno}: feature block already opened at line {start_if_line}")
ValueError: .../simdutf/include/simdutf/implementation.h:149: feature block already opened at line 86

./singleheader/amalgamate.py --with-utf8 --with-utf16