diff --git a/dev-lang/python/python-0.3.15.9999.ebuild b/dev-lang/python/python-0.3.15.9999.ebuild
index 26c49320ae820..9f5963fe67010 100644
--- a/dev-lang/python/python-0.3.15.9999.ebuild
+++ b/dev-lang/python/python-0.3.15.9999.ebuild
@@ -9,7 +9,7 @@ inherit autotools check-reqs flag-o-matic git-r3 linux-info
 inherit multiprocessing pax-utils toolchain-funcs
 
 PYVER="$(ver_cut 2-3)t"
-PATCHSET="python-gentoo-patches-3.14.0b1"
+PATCHSET="python-gentoo-patches-3.15.0a8"
 
 DESCRIPTION="Freethreading (no-GIL) version of Python programming language"
 HOMEPAGE="
@@ -515,10 +515,15 @@ src_test() {
 
 src_install() {
 	local libdir=${ED}/usr/lib/python${PYVER}
+	local build_dir=$(<pybuilddir.txt)
 
 	# -j1 hack for now for bug #843458
 	emake -j1 DESTDIR="${D}" TEST_MODULES=no altinstall
 
+	# Install build-details.json manually because it was randomly removed
+	# from altinstall in https://github.com/python/cpython/pull/142269.
+	cp "${build_dir}"/build-details.json "${libdir}"/ || die
+
 	# Fix collisions between different slots of Python.
 	rm "${ED}/usr/$(get_libdir)/libpython3.so" || die
 	# Fix collision with GIL-enabled build.
diff --git a/dev-lang/python/python-3.15.9999.ebuild b/dev-lang/python/python-3.15.9999.ebuild
index 97058a6f50c66..0544695447b6e 100644
--- a/dev-lang/python/python-3.15.9999.ebuild
+++ b/dev-lang/python/python-3.15.9999.ebuild
@@ -11,7 +11,7 @@ inherit autotools check-reqs flag-o-matic git-r3 linux-info llvm-r1
 inherit multiprocessing pax-utils toolchain-funcs
 
 PYVER=$(ver_cut 1-2)
-PATCHSET="python-gentoo-patches-3.14.0b1"
+PATCHSET="python-gentoo-patches-3.15.0a8"
 
 DESCRIPTION="An interpreted, interactive, object-oriented programming language"
 HOMEPAGE="
@@ -528,10 +528,14 @@ src_test() {
 
 src_install() {
 	local libdir=${ED}/usr/lib/python${PYVER}
+	local build_dir=$(<pybuilddir.txt)
 
 	# -j1 hack for now for bug #843458
 	emake -j1 DESTDIR="${D}" TEST_MODULES=no altinstall
 
+	# Install build-details.json manually because it was randomly removed
+	# from altinstall in https://github.com/python/cpython/pull/142269.
+	cp "${build_dir}"/build-details.json "${libdir}"/ || die
 	# Fix collisions between different slots of Python.
 	rm "${ED}/usr/$(get_libdir)/libpython3.so" || die