Re: [gentoo-dev] [PATCH] qt5-build.eclass: support sysroot builds

2020-03-27 Thread David Michael
On Fri, Mar 27, 2020 at 4:49 PM James Le Cuirot  wrote:
> On Fri, 27 Mar 2020 13:10:34 -0400
> David Michael  wrote:
>
> > I'd like to be able to install qt5 packages in a sysroot for staging,
> > and this is an initial patch for it.  The pkg-config variables might not
> > be required, but it seemed appropriate to pass the sysroot-configured
> > versions through the build.  There are a few caveats:
> >
> >   - The upstream configure scripts do some bad things like this:
> > https://code.qt.io/cgit/qt/qtbase.git/tree/configure.pri#n363
> > That makes the build fail for systems using lib64 (e.g. amd64).  I'm
> > able to work around this by defining PKG_CONFIG_LIBDIR for dev-qt/*.
>
> Indeed, that sucks. We should probably patch that out. I don't know
> what it means where it says "or use -pkg-config to override this test",
> do you?

I'm not sure, since -pkg-config is already being used by the eclass.
Maybe it was supposed to reference the -force-pkg-config option, which
I haven't tried.

> I suspect you could define PKG_CONFIG_LIBDIR=/ or anywhere that
> simply exists and it will still work because our wrapper redefines that
> variable anyway.
>
> >   - This isn't for real cross-compiling.  There are places where it
> > tries to execute cross-compiled programs that I haven't investigated
> > yet, so this is only for building a sysroot for an architecture
> > compatible with the build system for now.
>
> Understood. I did try to do cross-compiling with Qt4 once upon a time
> and I did make a little headway but it wasn't fun.
>
> >   - The qt packages depend on each other being installed in / as well as
> > the sysroot, so their ebuilds will need BDEPENDs added.
>
> I imagine you'd at least need qtcore for qmake and moc. Probably not
> the rest though?

I needed qtcore, qtgui, and qtwidgets in /, but it's possible there
are just bad configure scripts that I didn't dig into yet.  As for VLC
deps:
  - qtcore works as is
  - qtgui requires qtcore for bootstrap-private in /
  - qtwidgets requires qtgui in / for some opengl check
  - qtsvg and qtx11extras need qmake to build, but their packages will
be empty unless qtwidgets is installed in /

> >   - I've only gotten to testing a few packages that are dependencies of
> > other applications (like VLC), so I may be missing breakages.
> >
> > The patch basically just sets -sysroot when $SYSROOT is defined.  It
> > also needs to set -extprefix to the normal prefix, since otherwise it
> > would default to installing into /sysroot/prefix.  Is anyone involved in
> > qt maintenance more experienced with this and able to comment?
>
> I'm not the Qt guy but I am the cross guy. I'm not in a position to
> test this right now but it looks good and I love the simplicity of it.
> It's a hell of a lot simpler than Qt4 was. To be honest, we should be
> setting QMAKE_PKG_CONFIG regardless.



Re: [gentoo-dev] [PATCH] qt5-build.eclass: support sysroot builds

2020-03-27 Thread James Le Cuirot
On Fri, 27 Mar 2020 13:10:34 -0400
David Michael  wrote:

> I'd like to be able to install qt5 packages in a sysroot for staging,
> and this is an initial patch for it.  The pkg-config variables might not
> be required, but it seemed appropriate to pass the sysroot-configured
> versions through the build.  There are a few caveats:
> 
>   - The upstream configure scripts do some bad things like this:
> https://code.qt.io/cgit/qt/qtbase.git/tree/configure.pri#n363
> That makes the build fail for systems using lib64 (e.g. amd64).  I'm
> able to work around this by defining PKG_CONFIG_LIBDIR for dev-qt/*.

Indeed, that sucks. We should probably patch that out. I don't know
what it means where it says "or use -pkg-config to override this test",
do you? I suspect you could define PKG_CONFIG_LIBDIR=/ or anywhere that
simply exists and it will still work because our wrapper redefines that
variable anyway.

>   - This isn't for real cross-compiling.  There are places where it
> tries to execute cross-compiled programs that I haven't investigated
> yet, so this is only for building a sysroot for an architecture
> compatible with the build system for now.

Understood. I did try to do cross-compiling with Qt4 once upon a time
and I did make a little headway but it wasn't fun.

>   - The qt packages depend on each other being installed in / as well as
> the sysroot, so their ebuilds will need BDEPENDs added.

I imagine you'd at least need qtcore for qmake and moc. Probably not
the rest though?

>   - I've only gotten to testing a few packages that are dependencies of
> other applications (like VLC), so I may be missing breakages.
> 
> The patch basically just sets -sysroot when $SYSROOT is defined.  It
> also needs to set -extprefix to the normal prefix, since otherwise it
> would default to installing into /sysroot/prefix.  Is anyone involved in
> qt maintenance more experienced with this and able to comment?

I'm not the Qt guy but I am the cross guy. I'm not in a position to
test this right now but it looks good and I love the simplicity of it.
It's a hell of a lot simpler than Qt4 was. To be honest, we should be
setting QMAKE_PKG_CONFIG regardless.

-- 
James Le Cuirot (chewi)
Gentoo Linux Developer


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