Check whether version number complies with PEP 440

a24b7f9 exposed a problem where if the
version number does not comply with PEP 440, it may be normalized by
setuptools, but the build scripts are still looking for a wheel
containing the un-normalized version. This causes the build scripts to
fail to find the wheels that are created. To avoid this situation, we
now check the version number for PEP 440 compliance when building the
Python interface. This will allow non-compliant version number issues to
be caught locally.

modules/iknowpy/setup.py

@@ -43,6 +43,7 @@
 import itertools
 import os
 import platform
+import re
 import shutil
 import subprocess
 import sys
@@ -601,6 +602,14 @@ def find_wheel():
     return wheel_pattern_matches[0]
 
 
+def is_canonical_version(version):
+    """Return True if version is canonical according to PEP 440, False
+    otherwise."""
+    return re.match(
+        r'^([1-9][0-9]*!)?(0|[1-9][0-9]*)(\.(0|[1-9][0-9]*))*((a|b|rc)(0|[1-9][0-9]*))?(\.post(0|[1-9][0-9]*))?(\.dev(0|[1-9][0-9]*))?$',
+        version) is not None
+
+
 # set constants
 CACHE_DIR = 'dist/cache'
 
@@ -609,6 +618,8 @@ def find_wheel():
 with open('iknowpy/version.py') as version_file:
     exec(version_file.read(), version)
 version = version['__version__']
+if not is_canonical_version(version):
+    raise BuildError(f'Version {version!r} is not in PEP 440 canonical form')
 
 if 'ICUDIR' in os.environ:
     icudir = os.environ['ICUDIR']