freerdp3 fails to cross build from source as a Debian package. The
upstream build system has some support for cross building built into it.
There are two tools that are to be run during build. They're
sdl-common-res2bin and generate_argument_docbook. The build system takes
care of importing these during cross building, but nothing supplies them
in the Debian build. Generating these tools using CMake is a non-trivial
affair as many of the dependencies cannot be disabled, so we'd massively
increase Build-Depends for little value. I therefore propose manually
building these two components. Doing so is a little fragile admittedly.
A minor complication is that the upstream build system references
generate_argument_docbook via its native path and that has to be
patched. I'm attaching the resulting patch for your convenience. Please
let me know if this is acceptable.

Helmut

I'm commenting on a single aspect of the proposed patch
here, not about the bug itself.  Please also note this
hunk isn't needed anymore, since I removed the affected
lines entirely.

On Wed, 2 Oct 2024 20:43:26 +0200 Helmut Grohne <helmut@subdivi.de> wrote:
..

@@ -133,11 +168,13 @@
  	    -e "s$(xSEDx) $${o}=[^=]+=\.$(xSEDx)$(xSEDx)g;" \
  	obj-$(DEB_HOST_GNU_TYPE)/winpr/include/winpr/buildflags.h

+ifeq ($(filter nocheck,$(DEB_BUILD_OPTIONS)),)
  execute_after_dh_auto_build:
  	dh_auto_build --builddirectory=debian/testtmp

  execute_after_dh_auto_test:
  	dh_auto_test --builddirectory=debian/testtmp
+endif

This seems to be wrong way to do it, because debhelper doesn't
implement full make(1) machinery.  If we're to do this, it should
be done like:

  execute_after_dh_auto_build:
+ifeq ($(filter nocheck,$(DEB_BUILD_OPTIONS)),)
  	dh_auto_build --builddirectory=debian/testtmp
+endif

  execute_after_dh_auto_test:
+ifeq ($(filter nocheck,$(DEB_BUILD_OPTIONS)),)
  	dh_auto_test --builddirectory=debian/testtmp
+endif


In other words: keep the targets, but make them empty
based on condition.  Instead of conditionally hide the
targets, which confuses debhelper.

Thanks,

/mjt

sdl-common-res2bin and generate_argument_docbook were dropped upstream
with 3.9.0. manpages and resources are now generated with cmake.

Related upstream commits for reference:

c3a5387187501d4b55b4d410b88622157cedbf11 - generate_argument_docbook
fe590801a1b89f951eefae5184a610ce27349423 - sdl-common-res2bin