Similar to bug 2213635 but different.

+ cp -a gcc/libgccjit.so gcc/libgccjit.so.0 gcc/libgccjit.so.0.0.1 ../gcc/
+ cd ../gcc/
+ ln -sf xgcc x86_64-redhat-linux-gcc-13
+ cp -a Makefile Makefile.orig
+ sed -i -e '/^CHECK_TARGETS/s/$/ check-jit/' Makefile
+ touch -r Makefile.orig Makefile
+ rm Makefile.orig
+ make jit.sphinx.html
/bin/sh ../../gcc/../mkinstalldirs jit/sphinx-build
mkdir -p -- jit/sphinx-build
(cd ../../gcc/jit/docs && \
  make html BUILDDIR=/builddir/build/BUILD/gcc-13.1.1-20230426/obj-x86_64-redhat-linux/gcc/jit/sphinx-build )
make[1]: Entering directory '/builddir/build/BUILD/gcc-13.1.1-20230426/gcc/jit/docs'
sphinx-build -b html -d /builddir/build/BUILD/gcc-13.1.1-20230426/obj-x86_64-redhat-linux/gcc/jit/sphinx-build/doctrees   . /builddir/build/BUILD/gcc-13.1.1-20230426/obj-x86_64-redhat-linux/gcc/jit/sphinx-build/html
Running Sphinx v3.4.3
making output directory... done
WARNING: html_static_path entry '_static' does not exist
building [mo]: targets for 0 po files that are out of date
building [html]: targets for 35 source files that are out of date
updating environment: [new config] 35 added, 0 changed, 0 removed
reading sources... [  2%] cp/index
reading sources... [  5%] cp/intro/index
reading sources... [  8%] cp/intro/tutorial01
reading sources... [ 11%] cp/intro/tutorial02
reading sources... [ 14%] cp/intro/tutorial03
reading sources... [ 17%] cp/intro/tutorial04
reading sources... [ 20%] cp/topics/asm
reading sources... [ 22%] cp/topics/compilation
reading sources... [ 25%] cp/topics/contexts
reading sources... [ 28%] cp/topics/expressions
reading sources... [ 31%] cp/topics/functions
reading sources... [ 34%] cp/topics/index
reading sources... [ 37%] cp/topics/locations
reading sources... [ 40%] cp/topics/objects
reading sources... [ 42%] cp/topics/types
reading sources... [ 45%] index
reading sources... [ 48%] internals/index
reading sources... [ 51%] intro/index
reading sources... [ 54%] intro/tutorial01
reading sources... [ 57%] intro/tutorial02
reading sources... [ 60%] intro/tutorial03
reading sources... [ 62%] intro/tutorial04
reading sources... [ 65%] intro/tutorial05
reading sources... [ 68%] topics/asm
reading sources... [ 71%] topics/compatibility
reading sources... [ 74%] topics/compilation
reading sources... [ 77%] topics/contexts
reading sources... [ 80%] topics/expressions
reading sources... [ 82%] topics/function-pointers
reading sources... [ 85%] topics/functions
reading sources... [ 88%] topics/index
reading sources... [ 91%] topics/locations
reading sources... [ 94%] topics/objects
reading sources... [ 97%] topics/performance
reading sources... [100%] topics/types
looking for now-outdated files... none found
pickling environment... done
checking consistency... done
preparing documents... done
writing output... [  2%] cp/index
writing output... [  5%] cp/intro/index
writing output... [  8%] cp/intro/tutorial01
writing output... [ 11%] cp/intro/tutorial02
writing output... [ 14%] cp/intro/tutorial03
writing output... [ 17%] cp/intro/tutorial04
writing output... [ 20%] cp/topics/asm
Exception occurred:
  File "/usr/lib/python3.9/site-packages/sphinx/domains/c.py", line 2021, in direct_lookup
    for name, id_ in key.data:
ValueError: too many values to unpack (expected 2)
The full traceback has been saved in /tmp/sphinx-err-b9nhml6d.log, if you want to report the issue to the developers.
Please also report this if it was a user error, so that a better error message can be provided next time.
A bug report can be filed in the tracker at <https://github.com/sphinx-doc/sphinx/issues>. Thanks!
make[1]: Leaving directory '/builddir/build/BUILD/gcc-13.1.1-20230426/gcc/jit/docs'
make[1]: *** [Makefile:45: html] Error 2
make: *** [../../gcc/jit/Make-lang.in:306: jit.sphinx.html] Error 2

Full log: https://kojihub.stream.rdu2.redhat.com/koji/taskinfo?taskID=2307762

This worked in gcc-toolset-12-gcc.  I haven't checked yet how the libgccjit docs have changed.