[Plplot-devel] Native build problems when cross-compiling PLplot

[Sebastian E. <aw...@gm...>]

Hi everybody,

I'm currently trying to cross-compile PLplot for Linux/ppc64le,
Linux/aarch64 and MacOS/arm64 using the conda-forge toolchain [1].

[1]:https://github.com/conda-forge/plplot-feedstock/pull/1

>From the PLplot wiki [2] I figured I need a native build first, to get
access to some intermediary binaries, which are than used in a cross
build done in a second step. However, getting the native build running
in the cross environment is giving me some grief. Linking
lib/qsastime/tai-utc-gen in the native build fails for me because I
can't get CMake to *not* find and *not* prefer the sysroot of cross-
compiler (pc_libplplot_LINK_FLAGS is including the libm for the host
platform).

[2]:https://sourceforge.net/p/plplot/wiki/Building_PLplot_with_a_cross-compiler/

What I can't do is have two different environments here (native first
and cross later), because I run inside conda-build to make the
packaging automatic with the conda-forge toolchain for future PLplot
releases. While I can install a native PLplot version and point to its
prefix, this is insufficient to get lib/qsastime/tai-utc-gen and co for
the cross build.

I attached the log from the last build on Linux/aarch64, but you can
also find the logs online at Azure [1]. Note that I can run the Linux
builds with QEMU if cross-compiling is not possible (it is just very
slow), but I can't use hardware emulation for the MacOS/arm64 host.

Any pointers, tips or tricks are much appreciated.

All the best
Sebastian