meson: use Python script for version detection

[tinc] / version.py

diff --git a/version.py b/version.py
new file mode 100755 (executable)
index 0000000..ff491bb
--- /dev/null
+++ b/version.py
@@ -0,0 +1,26 @@
+#!/usr/bin/env python3
+
+from sys import argv, exit
+import subprocess as subp
+
+prefix = "release-"
+
+cmd = [
+    "git",
+    "describe",
+    "--always",
+    "--tags",
+    "--match=" + prefix + "*",
+]
+
+if "short" in argv:
+    cmd.append("--abbrev=0")
+
+result = subp.run(cmd, stdout=subp.PIPE, encoding="utf-8")
+version = result.stdout
+
+if not result.returncode and version and version.startswith(prefix):
+    version = version[len(prefix):].strip()
+
+print(version if version else "unknown", end="")
+exit(not version)