fix: setuptools_scm version detection for EL10/fc42+

- Add pyproject.toml with [tool.setuptools_scm] configuration
- Update .git_archival.txt to modern format (node, node-date, describe-name)
- Set SETUPTOOLS_SCM_PRETEND_VERSION in spec %build/%install sections
- Fix __about__.py version to be a string instead of integer
- Use spec version for non-tagged builds instead of resetting to 0

Fixes RPM build failures on EL10/fc42+ where setuptools_scm 6.0+ requires
proper configuration to parse version from git archives.

Author: dvershinin

.git_archival.txt

@@ -1 +1,4 @@
-ref-names: $Format:%D$
+node: $Format:%H$
+node-date: $Format:%cI$
+describe-name: $Format:%(describe:tags=true,match=*[0-9]*)$
+ref-names: $Format:%D$

fds.spec

@@ -141,6 +141,8 @@ sed -i '/ipaddress;/d' setup.py
 
 
 %build
+# Set version for setuptools_scm in case .git_archival.txt parsing fails
+export SETUPTOOLS_SCM_PRETEND_VERSION=%{version}
 %if %{with python2}
 %py2_build
 %endif
@@ -154,6 +156,8 @@ pandoc -s -t man README.md -o %{name}.1
 
 
 %install
+# Set version for setuptools_scm in case .git_archival.txt parsing fails
+export SETUPTOOLS_SCM_PRETEND_VERSION=%{version}
 %if %{with python2}
 %py2_install
 %endif

fds/__about__.py

@@ -1 +1 @@
-__version__ = 0
+__version__ = "0.0.0"

pyproject.toml

@@ -0,0 +1,6 @@
+[build-system]
+requires = ["setuptools>=45", "setuptools_scm[toml]>=6.0"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools_scm]
+fallback_version = "0.0.0"

utils/version-from-tag.sh

@@ -3,26 +3,34 @@
 # Print what is being run:
 set -x
 
+PKG=$(basename *.spec .spec)
+
 if TAG=$(git describe --exact-match --tags "$(git log -n1 --pretty='%h')" 2>/dev/null); then
   VER=$(echo "${TAG}" | grep --perl-regexp --only-matching '\d+\.\d+\.\d+')
+  sed -i "s@Version:.*@Version:        ${VER}@" "${PKG}.spec"
 else
-  TAG="v0"
-  VER=0
+  # For non-tagged builds, use the version from spec file (don't reset to 0)
+  VER=$(awk '/^Version:/ {print $2}' "${PKG}.spec")
+  TAG="v${VER}"
 fi
 
-PKG=$(basename *.spec .spec)
-
-sed -i "s@Version:.*@Version:        ${VER}@" "${PKG}.spec"
-
 echo "Creating github-like archive from current checkout, for rpmbuild"
-# by our convention, the spec file in git has Version: 0, so it will extract to <name>-0
+# The spec file in git has a version number, tagged builds update it from the tag
 # first create subst like ref-names: HEAD -> master, tag: v0.0.9 in .git_archival.txt
 # because we are creating archive ourselves
 # Build name is extracted dir name (without v!)
 BUILD_NAME="${PKG}-${VER}"
 mkdir "/tmp/${BUILD_NAME}"
 cp -aRp ./* "/tmp/${BUILD_NAME}/"
-echo "ref-names: HEAD -> master, tag: ${TAG}" > "/tmp/${BUILD_NAME}/.git_archival.txt"
+# Create .git_archival.txt with format expected by setuptools_scm 6.0+
+NODE=$(git rev-parse HEAD)
+NODE_DATE=$(git log -1 --format=%cI)
+cat > "/tmp/${BUILD_NAME}/.git_archival.txt" << EOF
+node: ${NODE}
+node-date: ${NODE_DATE}
+describe-name: ${TAG}
+ref-names: HEAD -> master, tag: ${TAG}
+EOF
 pushd /tmp || exit
 tar -czvf ./${TAG}.tar.gz "./${BUILD_NAME}"
 popd || exit