Re: Cross compiling with interpreter extension library

[Helmut Grohne <helmut@subdivi.de>]

Hi Keith,

On Mon, Sep 08, 2025 at 02:01:43PM -0700, Keith Packard wrote:
> Merged Build-Depends: debhelper-compat (= 12), debhelper (>= 12), libcairo2-dev, librsvg2-dev, libx11-dev (>= 2:1.4.99.901), libfreetype-dev, nickle (>= 2.73), build-essential:amd64, crossbuild-essential-arm64:amd64, apt-utils:amd64, libc-dev:arm64, libstdc++-dev:arm64
> Filtered Build-Depends: debhelper-compat (= 12), debhelper (>= 12), libcairo2-dev, librsvg2-dev, libx11-dev (>= 2:1.4.99.901), libfreetype-dev, nickle (>= 2.73), build-essential:amd64, crossbuild-essential-arm64:amd64, apt-utils:amd64, libc-dev:arm64, libstdc++-dev:arm64
> 
> The following additional packages will be installed:
> ...
>   cpp-aarch64-linux-gnu cross-exe-wrapper:arm64 crossbuild-essential-arm64
> ...
>   nickle:arm64 pango1.0-tools pkgconf:arm64 pkgconf-bin po-debconf python3
>   python3-minimal python3-packaging python3.13 python3.13-minimal qemu-user
> ...
> 
> Is there some sbuild magic which adds cross-exe-wrapper (and qemu-user)
> when it thinks it might be needed? Would splitting out the dev files
> from nickle resolve this?

libcairo2-dev Depends: libglib2.0-dev
libglib2.0-dev Depends: girepository-tools
girepository-tools Depends: native-architecture | cross-exe-wrapper

This is deep. Simon McVittie gave an entire talk in Cambridge about why
this is how it is. The very short version is that some reverse
dependencies of libglib2.0-dev don't actually need all of it and may be
happy with libgio-2.0-dev. Reducing libglib2.0-dev dependencies to
libgio-2.0-dev is ongoing work. Would you happen to have a good enough
understanding how how cairo uses it?

Helmut