Build on RHEL8.5/Python3.6 fails (numpy array issue?)

[ralphlange]

I'm building p4p as an EPICS module on a RHEL8.5 system with Python 3.6, numpy 1.14.3.

While a build of p4p 4.1.12 works fine, building 4.2.0 fails with:

/usr/bin/g++  -D_GNU_SOURCE -D_DEFAULT_SOURCE       -DPY_ARRAY_UNIQUE_SYMBOL=PVXS_PyArray_API -DPVXS_ENABLE_EXPERT_API  -D__PYX_EXTERN_C=extern   -D_X86_64_  -DUNIX  -Dlinux      -O3 -g   -Wall    -Wno-unused-result -Wsign-compare  -std=c++11  -mtune=generic      -m64 -std=c++11  -fPIC -I. -I../O.Common -I. -I. -I.. -I../../include/compiler/gcc -I../../include/os/Linux -I../../include    -I/opt/codac-7.3/epics/include/compiler/gcc -I/opt/codac-7.3/epics/include/os/Linux -I/opt/codac-7.3/epics/include       -I/opt/codac-7.3/include   -I/usr/lib64/python3.6/site-packages/numpy/core/include -I/usr/include/python3.6m -c _p4p.cpp
[WARN] _p4p.cpp: In function ‘int __pyx_pf_5numpy_7ndarray___getbuffer__(PyArrayObject*, Py_buffer*, int)’:
[ERROR] _p4p.cpp:18875:50: error: ‘NPY_C_CONTIGUOUS’ was not declared in this scope
[WARN] __pyx_t_2 = ((!(PyArray_CHKFLAGS(__pyx_v_self, NPY_C_CONTIGUOUS) != 0)) != 0);
[WARN] ^~~~~~~~~~~~~~~~
[WARN] _p4p.cpp:18875:50: note: suggested alternative: ‘PyBUF_C_CONTIGUOUS’
[WARN] __pyx_t_2 = ((!(PyArray_CHKFLAGS(__pyx_v_self, NPY_C_CONTIGUOUS) != 0)) != 0);
[WARN] ^~~~~~~~~~~~~~~~
[WARN] PyBUF_C_CONTIGUOUS
[ERROR] _p4p.cpp:18931:50: error: ‘NPY_F_CONTIGUOUS’ was not declared in this scope
[WARN] __pyx_t_2 = ((!(PyArray_CHKFLAGS(__pyx_v_self, NPY_F_CONTIGUOUS) != 0)) != 0);
[WARN] ^~~~~~~~~~~~~~~~
[WARN] _p4p.cpp:18931:50: note: suggested alternative: ‘PyBUF_F_CONTIGUOUS’
[WARN] __pyx_t_2 = ((!(PyArray_CHKFLAGS(__pyx_v_self, NPY_F_CONTIGUOUS) != 0)) != 0);
[WARN] ^~~~~~~~~~~~~~~~
[WARN] PyBUF_F_CONTIGUOUS
[ERROR] _p4p.cpp:19117:42: error: ‘PyArrayObject’ {aka ‘struct tagPyArrayObject’} has no member named ‘descr’
[WARN] __pyx_t_3 = ((PyObject *)__pyx_v_self->descr);
[WARN] ^~~~~
[WARN] In file included from /usr/include/python3.6m/pytime.h:6,
[WARN] from /usr/include/python3.6m/Python.h:77,
[WARN] from _p4p.cpp:4:
[WARN] _p4p.cpp: In function ‘void __pyx_f_5numpy_set_array_base(PyArrayObject*, PyObject*)’:
[ERROR] _p4p.cpp:20761:27: error: ‘PyArrayObject’ {aka ‘struct tagPyArrayObject’} has no member named ‘base’; did you mean ‘ob_base’?
[WARN] Py_XDECREF(__pyx_v_arr->base);
[WARN] ^~~~
[WARN] /usr/include/python3.6m/object.h:851:50: note: in definition of macro ‘Py_XDECREF’
[WARN] PyObject *_py_xdecref_tmp = (PyObject *)(op); \
[WARN] ^~
[ERROR] _p4p.cpp:20770:16: error: ‘PyArrayObject’ {aka ‘struct tagPyArrayObject’} has no member named ‘base’; did you mean ‘ob_base’?
[WARN] __pyx_v_arr->base = __pyx_v_baseptr;
[WARN] ^~~~
[WARN] ob_base
[WARN] _p4p.cpp: In function ‘PyObject* __pyx_f_5numpy_get_array_base(PyArrayObject*)’:
[ERROR] _p4p.cpp:20805:30: error: ‘PyArrayObject’ {aka ‘struct tagPyArrayObject’} has no member named ‘base’; did you mean ‘ob_base’?
[WARN] __pyx_t_1 = ((__pyx_v_arr->base == NULL) != 0);
[WARN] ^~~~
[WARN] ob_base
[WARN] In file included from /usr/include/python3.6m/pytime.h:6,
[WARN] from /usr/include/python3.6m/Python.h:77,
[WARN] from _p4p.cpp:4:
[ERROR] _p4p.cpp:20837:44: error: ‘PyArrayObject’ {aka ‘struct tagPyArrayObject’} has no member named ‘base’; did you mean ‘ob_base’?
[WARN] __Pyx_INCREF(((PyObject *)__pyx_v_arr->base));
[WARN] ^~~~
[WARN] /usr/include/python3.6m/object.h:786:19: note: in definition of macro ‘Py_INCREF’
[WARN] ((PyObject *)(op))->ob_refcnt++)
[WARN] ^~
[WARN] _p4p.cpp:20837:5: note: in expansion of macro ‘__Pyx_INCREF’
[WARN] __Pyx_INCREF(((PyObject *)__pyx_v_arr->base));
[WARN] ^~~~~~~~~~~~
[ERROR] _p4p.cpp:20838:41: error: ‘PyArrayObject’ {aka ‘struct tagPyArrayObject’} has no member named ‘base’; did you mean ‘ob_base’?
[WARN] __pyx_r = ((PyObject *)__pyx_v_arr->base);
[WARN] ^~~~
[WARN] ob_base
[WARN] make[2]: *** [/opt/codac-7.3/epics/configure/RULES_BUILD:267: _p4p.o] Error 1
[WARN] make[2]: *** Waiting for unfinished jobs....
[WARN] make[1]: *** [/opt/codac-7.3/epics/configure/RULES_ARCHS:58: install.linux-x86_64] Error 2
[WARN] make: *** [/opt/codac-7.3/epics/configure/RULES_DIRS:85: src.install] Error 2
make[2]: Leaving directory '.../p4p-4.2.0/src/O.linux-x86_64'

Looking at the commits, I assume some version requirement not being met, but I'm not sure which one.

[mdavidsaver]

I'm building p4p as an EPICS module on a RHEL8.5 system with Python 3.6, numpy 1.14.3.

Which cython version?

This compilation error looks like a mis-match between numpy and cython.