Use setuptools_scm for version handling.

This includes manual configuration to avoid
pypa/setuptools-scm#411.

Also `import setuptools_scm` directly in `setup.py` to make sure that
`0.0.0` is not used as version, see pypa/setuptools-scm#386.

pyproject.toml

@@ -1,7 +1,21 @@
+[build-system]
+requires = [
+  'setuptools >= 42',
+  'wheel',
+  'setuptools_scm[toml]>=3.4',
+]
+
 [tool.black]
 line-ngth = 80
 target-version = ['py37']
 
 [tool.isort]
 line_length = 80
 known_third_party = ['absl', 'construct', 'hexdump', 'pcapng']
+
+[tool.setuptools_scm]
+# Until a new version of setuptools_scm with a fix for the following issue is
+# released, override the default configuration here.
+# https://github.com/pypa/setuptools_scm/issues/411
+tag_regex = '^(?:[\w-]+-)?(?P<version>[vV]?\d+(?:\.\d+){0,2}[^\+]*)(?:\+.*)?$'
+git_describe_command = 'git describe --dirty --tags --long --match *[0-9]*'

setup.py

@@ -21,6 +21,8 @@
 from setuptools import find_packages, setup
 from setuptools.command.test import test as TestCommand
 
+import setuptools_scm  # Ensure it's present.
+
 test_required = [
     "absl-py",
     "construct>=2.9",
@@ -41,7 +43,6 @@
 
 setup(
     name="usbmon-tools",
-    version="1",
     description="usbmon processing utilities (for Linux and Windows captures).",
     long_description=long_description,
     long_description_content_type="text/markdown",
@@ -62,5 +63,5 @@
     package_data={package: ["py.typed"] for package in all_packages},
     install_requires=["construct>=2.9", "hexdump", "python-pcapng>=1.0",],
     tests_require=test_required,
-    extras_require={"dev": test_required + ["pre-commit"],},
+    extras_require={"dev": test_required + ["pre-commit", "setuptools_scm"],},
 )