changes on cython master broke the pandas build

[tacaswell]

With current cython master pandas does not build. Bisecting identifies the current latest commit (
5204d86 ) as the first bad commit.

attn @WillAyd

(bleeding) ✔  ~/source/other_source/pandas [master {pandas/master}|✚ 2]
jupiter@15:19  ➤  pip install -v .
Non-user install because user site-packages disabled
Created temporary directory: /tmp/pip-ephem-wheel-cache-zcmyaxf3
Created temporary directory: /tmp/pip-req-tracker-dfm6xgbp
Initialized build tracking at /tmp/pip-req-tracker-dfm6xgbp
Created build tracker: /tmp/pip-req-tracker-dfm6xgbp
Entered build tracker: /tmp/pip-req-tracker-dfm6xgbp
Created temporary directory: /tmp/pip-install-_tjupc3v
Processing /home/tcaswell/source/other_source/pandas
  Created temporary directory: /tmp/pip-req-build-eh2hlgu3
  Added file:///home/tcaswell/source/other_source/pandas to build tracker '/tmp/pip-req-tracker-dfm6xgbp'
    Running setup.py (path:/tmp/pip-req-build-eh2hlgu3/setup.py) egg_info for package from file:///home/tcaswell/source/other_source/pandas
    Running command python setup.py egg_info
    warning: pandas/_libs/groupby.pyx:1101:26: Unreachable code

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
        cdef Py_ssize_t itemsize
        cdef bint dtype_signed
        cdef char kind
        itemsize = -1
        cdef bint ___pyx_int64_t_is_signed
        ___pyx_int64_t_is_signed = not (<___pyx_int64_t> -1 > 0)
                                        ^
    ------------------------------------------------------------

    (tree fragment):19:37: '___pyx_int64_t' is not a type identifier

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
        cdef char kind
        itemsize = -1
        cdef bint ___pyx_int64_t_is_signed
        ___pyx_int64_t_is_signed = not (<___pyx_int64_t> -1 > 0)
        cdef bint ___pyx_uint64_t_is_signed
        ___pyx_uint64_t_is_signed = not (<___pyx_uint64_t> -1 > 0)
                                         ^
    ------------------------------------------------------------

    (tree fragment):21:38: '___pyx_uint64_t' is not a type identifier

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: undeclared name not builtin: ___pyx_int64_t

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: '___pyx_int64_t' redeclared

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
        ctypedef struct __Pyx_memviewslice:
            void *memview

        void __PYX_XDEC_MEMVIEW(__Pyx_memviewslice *, int have_gil)
        bint __pyx_memoryview_check(object)
        ctypedef long long ___pyx_int64_t "__pyx_t_5numpy_int64_t"
       ^
    ------------------------------------------------------------

    __pyxutil:15:4: Previous declaration is here

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: undeclared name not builtin: ___pyx_uint64_t

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: '___pyx_uint64_t' redeclared

    Error compiling Cython file:
    ------------------------------------------------------------
    ...

        void __PYX_XDEC_MEMVIEW(__Pyx_memviewslice *, int have_gil)
        bint __pyx_memoryview_check(object)
        ctypedef long long ___pyx_int64_t "__pyx_t_5numpy_int64_t"
        ctypedef double ___pyx_float64_t "__pyx_t_5numpy_float64_t"
        ctypedef unsigned long long ___pyx_uint64_t "__pyx_t_5numpy_uint64_t"
       ^
    ------------------------------------------------------------

    __pyxutil:17:4: Previous declaration is here

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: undeclared name not builtin: ___pyx_float64_t

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: '___pyx_float64_t' redeclared

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            void *memview

        void __PYX_XDEC_MEMVIEW(__Pyx_memviewslice *, int have_gil)
        bint __pyx_memoryview_check(object)
        ctypedef long long ___pyx_int64_t "__pyx_t_5numpy_int64_t"
        ctypedef double ___pyx_float64_t "__pyx_t_5numpy_float64_t"
       ^
    ------------------------------------------------------------

    __pyxutil:16:4: Previous declaration is here

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: undeclared name not builtin: ___pyx_int64_t

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: '___pyx_int64_t' redeclared

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: Previous declaration is here

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: undeclared name not builtin: ___pyx_float64_t

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: '___pyx_float64_t' redeclared

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: Previous declaration is here

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: undeclared name not builtin: ___pyx_uint64_t

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: '___pyx_uint64_t' redeclared

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: Previous declaration is here

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
        cdef Py_ssize_t itemsize
        cdef bint dtype_signed
        cdef char kind
        itemsize = -1
        cdef bint ___pyx_int64_t_is_signed
        ___pyx_int64_t_is_signed = not (<___pyx_int64_t> -1 > 0)
                                        ^
    ------------------------------------------------------------

    (tree fragment):19:37: '___pyx_int64_t' is not a type identifier

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
        cdef char kind
        itemsize = -1
        cdef bint ___pyx_int64_t_is_signed
        ___pyx_int64_t_is_signed = not (<___pyx_int64_t> -1 > 0)
        cdef bint ___pyx_uint64_t_is_signed
        ___pyx_uint64_t_is_signed = not (<___pyx_uint64_t> -1 > 0)
                                         ^
    ------------------------------------------------------------

    (tree fragment):21:38: '___pyx_uint64_t' is not a type identifier

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: undeclared name not builtin: ___pyx_int64_t

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: '___pyx_int64_t' redeclared

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: Previous declaration is here

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: undeclared name not builtin: ___pyx_uint64_t

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: '___pyx_uint64_t' redeclared

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: Previous declaration is here

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: undeclared name not builtin: ___pyx_float64_t

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: '___pyx_float64_t' redeclared

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            values = [self.right, self.left]

            sort_order = np.lexsort(values)
            return is_monotonic(sort_order, False)[0]

        def get_indexer(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:122:4: Previous declaration is here

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: undeclared name not builtin: ___pyx_int64_t

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: '___pyx_int64_t' redeclared

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: Previous declaration is here

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: undeclared name not builtin: ___pyx_float64_t

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: '___pyx_float64_t' redeclared

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: Previous declaration is here

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: undeclared name not builtin: ___pyx_uint64_t

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: '___pyx_uint64_t' redeclared

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
                    raise KeyError(
                        'indexer does not intersect a unique set of intervals')
                old_len = result.data.n
            return result.to_array().astype('intp')

        def get_indexer_non_unique(self, scalar_t[:] target):
       ^
    ------------------------------------------------------------

    pandas/_libs/intervaltree.pxi:150:4: Previous declaration is here
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-req-build-eh2hlgu3/setup.py", line 794, in <module>
        setup_package()
      File "/tmp/pip-req-build-eh2hlgu3/setup.py", line 764, in setup_package
        ext_modules=maybe_cythonize(extensions, compiler_directives=directives),
      File "/tmp/pip-req-build-eh2hlgu3/setup.py", line 537, in maybe_cythonize
        return cythonize(extensions, *args, **kwargs)
      File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/Cython/Build/Dependencies.py", line 1105, in cythonize
        cythonize_one(*args)
      File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/Cython/Build/Dependencies.py", line 1263, in cythonize_one
        raise CompileError(None, pyx_file)
    Cython.Compiler.Errors.CompileError: pandas/_libs/interval.pyx
    Compiling pandas/_libs/algos.pyx because it changed.
    Compiling pandas/_libs/groupby.pyx because it changed.
    Compiling pandas/_libs/hashing.pyx because it changed.
    Compiling pandas/_libs/hashtable.pyx because it changed.
    Compiling pandas/_libs/index.pyx because it changed.
    Compiling pandas/_libs/indexing.pyx because it changed.
    Compiling pandas/_libs/internals.pyx because it changed.
    Compiling pandas/_libs/interval.pyx because it changed.
    Compiling pandas/_libs/join.pyx because it changed.
    Compiling pandas/_libs/lib.pyx because it changed.
    Compiling pandas/_libs/missing.pyx because it changed.
    Compiling pandas/_libs/parsers.pyx because it changed.
    Compiling pandas/_libs/reduction.pyx because it changed.
    Compiling pandas/_libs/ops.pyx because it changed.
    Compiling pandas/_libs/ops_dispatch.pyx because it changed.
    Compiling pandas/_libs/properties.pyx because it changed.
    Compiling pandas/_libs/reshape.pyx because it changed.
    Compiling pandas/_libs/sparse.pyx because it changed.
    Compiling pandas/_libs/tslib.pyx because it changed.
    Compiling pandas/_libs/tslibs/c_timestamp.pyx because it changed.
    Compiling pandas/_libs/tslibs/ccalendar.pyx because it changed.
    Compiling pandas/_libs/tslibs/conversion.pyx because it changed.
    Compiling pandas/_libs/tslibs/fields.pyx because it changed.
    Compiling pandas/_libs/tslibs/frequencies.pyx because it changed.
    Compiling pandas/_libs/tslibs/nattype.pyx because it changed.
    Compiling pandas/_libs/tslibs/np_datetime.pyx because it changed.
    Compiling pandas/_libs/tslibs/offsets.pyx because it changed.
    Compiling pandas/_libs/tslibs/parsing.pyx because it changed.
    Compiling pandas/_libs/tslibs/period.pyx because it changed.
    Compiling pandas/_libs/tslibs/resolution.pyx because it changed.
    Compiling pandas/_libs/tslibs/strptime.pyx because it changed.
    Compiling pandas/_libs/tslibs/timedeltas.pyx because it changed.
    Compiling pandas/_libs/tslibs/timestamps.pyx because it changed.
    Compiling pandas/_libs/tslibs/timezones.pyx because it changed.
    Compiling pandas/_libs/tslibs/tzconversion.pyx because it changed.
    Compiling pandas/_libs/testing.pyx because it changed.
    Compiling pandas/_libs/window/aggregations.pyx because it changed.
    Compiling pandas/_libs/window/indexers.pyx because it changed.
    Compiling pandas/_libs/writers.pyx because it changed.
    Compiling pandas/io/sas/sas.pyx because it changed.
    [ 1/40] Cythonizing pandas/_libs/algos.pyx
    [ 2/40] Cythonizing pandas/_libs/groupby.pyx
    [ 3/40] Cythonizing pandas/_libs/hashing.pyx
    [ 4/40] Cythonizing pandas/_libs/hashtable.pyx
    [ 5/40] Cythonizing pandas/_libs/index.pyx
    [ 6/40] Cythonizing pandas/_libs/indexing.pyx
    [ 7/40] Cythonizing pandas/_libs/internals.pyx
    [ 8/40] Cythonizing pandas/_libs/interval.pyx
Cleaning up...
  Removing source in /tmp/pip-req-build-eh2hlgu3
Removed file:///home/tcaswell/source/other_source/pandas from build tracker '/tmp/pip-req-tracker-dfm6xgbp'
Removed build tracker: '/tmp/pip-req-tracker-dfm6xgbp'
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
Exception information:
Traceback (most recent call last):
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/pip/_internal/cli/base_command.py", line 186, in _main
    status = self.run(options, args)
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/pip/_internal/commands/install.py", line 331, in run
    resolver.resolve(requirement_set)
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/pip/_internal/legacy_resolve.py", line 177, in resolve
    discovered_reqs.extend(self._resolve_one(requirement_set, req))
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/pip/_internal/legacy_resolve.py", line 333, in _resolve_one
    abstract_dist = self._get_abstract_dist_for(req_to_install)
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/pip/_internal/legacy_resolve.py", line 282, in _get_abstract_dist_for
    abstract_dist = self.preparer.prepare_linked_requirement(req)
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/pip/_internal/operations/prepare.py", line 515, in prepare_linked_requirement
    abstract_dist = _get_prepared_distribution(
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/pip/_internal/operations/prepare.py", line 95, in _get_prepared_distribution
    abstract_dist.prepare_distribution_metadata(finder, build_isolation)
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/pip/_internal/distributions/sdist.py", line 40, in prepare_distribution_metadata
    self.req.prepare_metadata()
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/pip/_internal/req/req_install.py", line 564, in prepare_metadata
    self.metadata_directory = self._generate_metadata()
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/pip/_internal/req/req_install.py", line 538, in _generate_metadata
    return generate_metadata_legacy(
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/pip/_internal/operations/build/metadata_legacy.py", line 115, in generate_metadata
    call_subprocess(
  File "/home/tcaswell/.virtualenvs/bleeding/lib/python3.9/site-packages/pip/_internal/utils/subprocess.py", line 242, in call_subprocess
    raise InstallationError(exc_msg)
pip._internal.exceptions.InstallationError: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

[da-woods]

Most of it is probably related to #3544 and fixed by #3546. If it's possible to report whether the fix works that'd be nice.

Quick summary is: double underscore names were changed so they followed Python rules and get mangled within a class. This looks like a bad idea in hindsight since (a) a lot of C names start with double underscores and (b) a lot of people have liked to use double underscores in their code.

---

I'm slightly surprised at where the your bisection points to, so it's possible that I've misidentified the error.

[tacaswell]

@da-woods It builds with your branch, but it does not contain what I think is the offending commit. If I cherry-pick the tip of master to your branch it also works.

[scoder]

Thanks for the report. Don't really know why it breaks (seems to be related to memory views), but it's not an important commit, so I just reverted it.

[tacaswell]

Reverting that commit does not fix the problem. I'm re-running the bisection, hopefully I didn't make a mistake the first time....

[tacaswell]

Sorry, I screwed up. I re-ran the bisect and got

git bisect start
# good: [f18e3c9f9ce35ebf2cf2713775f35c47351e9c15] Make "cimport numpy" without import_array() safer by automatically calling it (GH-3524)
git bisect good f18e3c9f9ce35ebf2cf2713775f35c47351e9c15
# bad: [203ec86c39165c4001aa9238268f1911db1e8728] Update and split changelog for 3.0a2.
git bisect bad 203ec86c39165c4001aa9238268f1911db1e8728
# good: [090809daa9f8332fc5f68c498508383bd2f8d5d6] Disable the PEP-487 test in PyPy because it fails in travis (PyPy 7.1.1).
git bisect good 090809daa9f8332fc5f68c498508383bd2f8d5d6
# good: [0917df8f32515daa0c67d0caf2104462aebd36ae] Guard helper function against missing usage when direct type slot access is disabled.
git bisect good 0917df8f32515daa0c67d0caf2104462aebd36ae
# good: [3de7a4b8fb7ce045222e13ca02541f6a70e89c2e] Tune some internal calls into fastcall/vectorcall (GH-3540)
git bisect good 3de7a4b8fb7ce045222e13ca02541f6a70e89c2e
# bad: [b709334b7af7cbafa017a8f27dc9bbeafda5af94] Remove unused import.
git bisect bad b709334b7af7cbafa017a8f27dc9bbeafda5af94
# bad: [abeb082098c13e243a2e2658f9eb45f1c151b091] Mangle __arg argument names in methods (GH-3123)
git bisect bad abeb082098c13e243a2e2658f9eb45f1c151b091
# first bad commit: [abeb082098c13e243a2e2658f9eb45f1c151b091] Mangle __arg argument names in methods (GH-3123)

which makes a lot more sense and points to @da-woods 's PR #3546 actually being the fix.

[scoder]

Ok, thanks for the update. I put the commit back in that I had reverted and will merge #3546 then.

[tacaswell]

happy to report the master branches are building together again :)

Thank you for you quick response and sorry again for the incorrect initial assessment.