[PATCH 3/3] distutils-r1.eclass: Align DISTUTILS_USE_PEP517 to package names

Align the few mismatched DISTUTILS_USE_PEP517 values to match the names
of the packages providing specific backends.  Specifically:

- flit → flit-core
- flit_scm → flit-scm
- jupyter → jupyter-packaging
- poetry → poetry-core

The old values are still accepted prior to EAPI 9, and we do not emit
a warning since there is no strong incentive to hurry the update.

While at it, refactor the code to avoid repeating the package names
unnecessarily.  This also implies removing some of the version
constraints that are old enough to be insignificant.

Signed-off-by: Michał Górny <[email protected]>
---
 eclass/distutils-r1.eclass | 154 ++++++++++---------------------------
 1 file changed, 41 insertions(+), 113 deletions(-)

diff --git a/eclass/distutils-r1.eclass b/eclass/distutils-r1.eclass
index 735861ef09359..f3b98c189ce6a 100644
--- a/eclass/distutils-r1.eclass
+++ b/eclass/distutils-r1.eclass
@@ -94,38 +94,16 @@
 # @PRE_INHERIT
 # @REQUIRED
 # @DESCRIPTION:
-# Specifies the PEP517 build system used for the package.  Currently,
-# the following values are supported:
+# Specifies the PEP517 build system used for the package.  Normally,
+# the values match the name of the package providing this backend.
 #
-# - flit - flit-core backend
+# The currently supported backends are: flit-core, flit-scm, hatchling,
+# jupyter-packaging, maturin, meson-python, pbr, pdm-backend,
+# poetry-core, scikit-build-core, setuptools, sip, uv-build.
 #
-# - flit_scm - flit_scm backend
-#
-# - hatchling - hatchling backend (from hatch)
-#
-# - jupyter - jupyter_packaging backend
-#
-# - maturin - maturin backend
-#
-# - meson-python - meson-python (mesonpy) backend
-#
-# - no - no PEP517 build system (see below)
-#
-# - pbr - pbr backend
-#
-# - pdm-backend - pdm.backend backend
-#
-# - poetry - poetry-core backend
-#
-# - scikit-build-core - scikit-build-core backend
-#
-# - setuptools - distutils or setuptools (incl. legacy mode)
-#
-# - sip - sipbuild backend
-#
-# - standalone - standalone/local build systems
-#
-# - uv-build - uv-build backend (using dev-python/uv)
+# Additionally, two special values are supported: "no" to indicate
+# no PEP517 build system, and "standalone" to indicate a standalone
+# (local to the package) build backend.  Both are described further on.
 #
 # The variable needs to be set before the inherit line.  If another
 # value than "standalone" and "no" is used, The eclass adds appropriate
@@ -235,32 +213,42 @@ else
 fi
 
 _distutils_set_globals() {
+	# convert deprecated values
+	if [[ ${EAPI} == [78] ]]; then
+		case ${DISTUTILS_USE_PEP517} in
+			flit)
+				DISTUTILS_USE_PEP517=flit-core
+				;;
+			flit_scm)
+				DISTUTILS_USE_PEP517=flit-scm
+				;;
+			jupyter)
+				DISTUTILS_USE_PEP517=jupyter-packaging
+				;;
+			poetry)
+				DISTUTILS_USE_PEP517=poetry-core
+				;;
+		esac
+	fi
+
 	local rdep bdep
 	bdep='
 		>=dev-python/gpep517-16[${PYTHON_USEDEP}]
 	'
 	case ${DISTUTILS_USE_PEP517} in
-		flit)
-			bdep+='
-				>=dev-python/flit-core-3.11.0[${PYTHON_USEDEP}]
-			'
+		flit-core|hatchling|jupyter-packaging|meson-python|pbr|pdm-backend)
+			;&
+		poetry-core|scikit-build-core|setuptools|sip|uv-build)
+			bdep+="
+				dev-python/${DISTUTILS_USE_PEP517}[${PYTHON_USEDEP}]
+			"
 			;;
-		flit_scm)
+		flit-scm)
 			bdep+='
 				>=dev-python/flit-core-3.11.0[${PYTHON_USEDEP}]
 				>=dev-python/flit-scm-1.7.0[${PYTHON_USEDEP}]
 			'
 			;;
-		hatchling)
-			bdep+='
-				>=dev-python/hatchling-1.27.0[${PYTHON_USEDEP}]
-			'
-			;;
-		jupyter)
-			bdep+='
-				>=dev-python/jupyter-packaging-0.12.3[${PYTHON_USEDEP}]
-			'
-			;;
 		maturin)
 			bdep+='
 				>=dev-util/maturin-1.8.2[${PYTHON_USEDEP}]
@@ -270,48 +258,8 @@ _distutils_set_globals() {
 			# undo the generic deps added above
 			bdep=
 			;;
-		meson-python)
-			bdep+='
-				>=dev-python/meson-python-0.17.1[${PYTHON_USEDEP}]
-			'
-			;;
-		pbr)
-			bdep+='
-				>=dev-python/pbr-6.1.1[${PYTHON_USEDEP}]
-			'
-			;;
-		pdm-backend)
-			bdep+='
-				>=dev-python/pdm-backend-2.4.3[${PYTHON_USEDEP}]
-			'
-			;;
-		poetry)
-			bdep+='
-				>=dev-python/poetry-core-2.1.1[${PYTHON_USEDEP}]
-			'
-			;;
-		scikit-build-core)
-			bdep+='
-				>=dev-python/scikit-build-core-0.11.5[${PYTHON_USEDEP}]
-			'
-			;;
-		setuptools)
-			bdep+='
-				>=dev-python/setuptools-78.1.0[${PYTHON_USEDEP}]
-			'
-			;;
-		sip)
-			bdep+='
-				>=dev-python/sip-6.10.0[${PYTHON_USEDEP}]
-			'
-			;;
 		standalone)
 			;;
-		uv-build)
-			bdep+='
-				dev-python/uv-build[${PYTHON_USEDEP}]
-			'
-			;;
 		*)
 			die "Unknown DISTUTILS_USE_PEP517=${DISTUTILS_USE_PEP517}"
 			;;
@@ -742,12 +690,12 @@ _distutils-r1_print_package_versions() {
 		)
 	fi
 	case ${DISTUTILS_USE_PEP517} in
-		flit)
+		flit-core|meson-python|poetry-core|scikit-build-core|sip)
 			packages+=(
-				dev-python/flit-core
+				"dev-python/${DISTUTILS_USE_PEP517}"
 			)
 			;;
-		flit_scm)
+		flit-scm)
 			packages+=(
 				dev-python/flit-core
 				dev-python/flit-scm
@@ -761,7 +709,7 @@ _distutils-r1_print_package_versions() {
 				dev-python/hatch-vcs
 			)
 			;;
-		jupyter)
+		jupyter-packaging)
 			packages+=(
 				dev-python/jupyter-packaging
 				dev-python/setuptools
@@ -777,11 +725,6 @@ _distutils-r1_print_package_versions() {
 		no)
 			return
 			;;
-		meson-python)
-			packages+=(
-				dev-python/meson-python
-			)
-			;;
 		pbr)
 			packages+=(
 				dev-python/pbr
@@ -795,16 +738,6 @@ _distutils-r1_print_package_versions() {
 				dev-python/setuptools
 			)
 			;;
-		poetry)
-			packages+=(
-				dev-python/poetry-core
-			)
-			;;
-		scikit-build-core)
-			packages+=(
-				dev-python/scikit-build-core
-			)
-			;;
 		setuptools)
 			packages+=(
 				dev-python/setuptools
@@ -813,11 +746,6 @@ _distutils-r1_print_package_versions() {
 				dev-python/wheel
 			)
 			;;
-		sip)
-			packages+=(
-				dev-python/sip
-			)
-			;;
 		uv-build)
 			packages+=(
 				dev-python/uv
@@ -867,16 +795,16 @@ _distutils-r1_key_to_backend() {
 
 	local key=${1}
 	case ${key} in
-		flit)
+		flit-core)
 			echo flit_core.buildapi
 			;;
-		flit_scm)
+		flit-scm)
 			echo flit_scm:buildapi
 			;;
 		hatchling)
 			echo hatchling.build
 			;;
-		jupyter)
+		jupyter-packaging)
 			echo jupyter_packaging.build_api
 			;;
 		maturin)
@@ -891,7 +819,7 @@ _distutils-r1_key_to_backend() {
 		pdm-backend)
 			echo pdm.backend
 			;;
-		poetry)
+		poetry-core)
 			echo poetry.core.masonry.api
 			;;
 		scikit-build-core)