games-emulation/dosbox-x: Update for upstream's rolling release adoption

Without a clear explanation, the upstream of this package has stopped
tagging releases and willy-nilly switched to "continuously built"
"nightly builds" (a.k.a. prone-to-break-on-any-day binaries put for user
downloads at an obscure place).  To allow Gentoo users to use recent
versions of this package without having to resort to the live ebuild, we
have no choice other than to make new non-live ebuilds based on GitHub
snapshot tarballs from now on.

Signed-off-by: Yuan Liao <liaoyuan@gmail.com>

games-emulation/dosbox-x/dosbox-x-2022.08.0.ebuild

@@ -1,6 +1,8 @@
 # Copyright 2022 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
+# Note: This is the last release (non-pre-release) tagged by upstream
+
 EAPI=8
 
 inherit autotools flag-o-matic toolchain-funcs xdg

games-emulation/dosbox-x/dosbox-x-9999.ebuild

@@ -3,14 +3,24 @@
 
 EAPI=8
 
-inherit autotools toolchain-funcs xdg
+inherit autotools readme.gentoo-r1 toolchain-funcs xdg
 
 if [[ "${PV}" == 9999 ]]; then
 	inherit git-r3
 	EGIT_REPO_URI="https://github.com/joncampbell123/dosbox-x.git"
 else
-	SRC_URI="https://github.com/joncampbell123/dosbox-x/archive/dosbox-x-windows-v${PV}.tar.gz"
-	S="${WORKDIR}/${PN}-${PN}-windows-v${PV}"
+	# https://github.com/joncampbell123/dosbox-x/discussions/3862
+	GIT_COMMIT=""
+	DOC_CONTENTS="
+		DOSBox-X upstream has stopped making releases.  Therefore, this
+		package has installed a copy of DOSBox-X built from an upstream
+		repository snapshot at the following Git commit:\n
+		\n
+		${GIT_COMMIT}
+	"
+
+	SRC_URI="https://github.com/joncampbell123/dosbox-x/archive/${GIT_COMMIT}.tar.gz -> ${P}.tar.gz"
+	S="${WORKDIR}/${PN}-${GIT_COMMIT}"
 	KEYWORDS="~amd64"
 fi
 
@@ -126,6 +136,11 @@ src_test() {
 	"${@}" || die "Unit tests failed"
 }
 
+src_install() {
+	default
+	[[ -n "${DOC_CONTENTS}" ]] && readme.gentoo_create_doc
+}
+
 pkg_preinst() {
 	xdg_pkg_preinst
 
@@ -148,6 +163,11 @@ pkg_preinst() {
 pkg_postinst() {
 	xdg_pkg_postinst
 
+	if ! has "${PVR}" ${REPLACING_VERSIONS} && [[ -n "${DOC_CONTENTS}" ]]; then
+		FORCE_PRINT_ELOG=1
+		readme.gentoo_print_elog
+	fi
+
 	if [[ "${PRINT_NOTES_FOR_DEBUGGER}" ]]; then
 		elog
 		elog "Note on the Debugger"