msys2-runtime: attempt to use makepkg's split debuginfo feature

[jeremyd2019]

To avoid additional changes to msys2-runtime's build (such as changing flags due to 'debug' being set), I didn't set debug at the top level of the PKGBUILD, but rather just in the msys2-runtime package. This means that makepkg didn't attempt to actually package an msys2-runtime-debug package, so I included the files in msys2-runtime-devel.

It doesn't look like the debug info produced is large enough to be complete, and objdump seems to back this up. Also, there are some extra files around the .exe files (whatever.exe.debug.exe in addition to some having whatever.exe.debug which is the name I would expect).

I think the makepkg procedure to produce split debuginfo is broken, but I wanted to open this as a draft to start the discussion.

Fixes #4595

[jeremyd2019]

An alternative to this approach would be the below patch, which results in the same msys-2.0.dbg file as before. I don't know which would be preferred.

diff --git a/msys2-runtime/PKGBUILD b/msys2-runtime/PKGBUILD
index a889ddf9279..787a1fcda38 100644
--- a/msys2-runtime/PKGBUILD
+++ b/msys2-runtime/PKGBUILD
@@ -4,7 +4,7 @@
 pkgbase=msys2-runtime
 pkgname=('msys2-runtime' 'msys2-runtime-devel')
 pkgver=3.5.3
-pkgrel=2
+pkgrel=3
 pkgdesc="Cygwin POSIX emulation engine"
 arch=('x86_64')
 url="https://www.cygwin.com/"
@@ -214,6 +214,11 @@ build() {
   LC_ALL=C make -j1 DESTDIR="${srcdir}"/dest install
 
   rm -rf "${srcdir}"/dest/etc
+
+  # split debug info from msys-2.0.dll
+  objcopy --add-gnu-debuglink=/dev/null --only-keep-debug "${srcdir}"/dest/usr/bin/msys-2.0.dll "${srcdir}"/dest/usr/bin/msys-2.0.dbg
+  objcopy -g --add-gnu-debuglink="${srcdir}"/dest/usr/bin/msys-2.0.dbg "${srcdir}"/dest/usr/bin/msys-2.0.dll "${srcdir}"/dest/usr/bin/msys-2.0.dll.new
+  mv -f "${srcdir}"/dest/usr/bin/msys-2.0.dll.new "${srcdir}"/dest/usr/bin/msys-2.0.dll
 }
 
 package_msys2-runtime() {
@@ -228,6 +233,7 @@ package_msys2-runtime() {
   rm -f "${pkgdir}"/usr/bin/cyglsa.dll
   rm -f "${pkgdir}"/usr/bin/cyglsa64.dll
   rm -f "${pkgdir}"/usr/bin/cygserver-config
+  rm -f "${pkgdir}"/usr/bin/msys-2.0.dbg
   cp -rf "${srcdir}"/dest/usr/share "${pkgdir}"/usr/
 }
 
@@ -236,8 +242,10 @@ package_msys2-runtime-devel() {
   depends=("msys2-runtime=${pkgver}")
   conflicts=('libcatgets-devel' 'msys2-runtime-3.4-devel' 'msys2-runtime-3.5-devel')
   replaces=('libcatgets-devel' 'msys2-runtime-3.5-devel')
+  options=('!strip')
 
   mkdir -p "${pkgdir}"/usr/bin
+  cp -f "${srcdir}"/dest/usr/bin/msys-2.0.dbg "${pkgdir}"/usr/bin/
   cp -rLf "${srcdir}"/dest/usr/${CHOST}/include "${pkgdir}"/usr/
   rm -f "${pkgdir}"/usr/include/iconv.h
   rm -f "${pkgdir}"/usr/include/unctrl.h

[jeremyd2019]

I'm inclined to go with the msys-2.0.dbg version. Closing this