Bug#978153: libgphobos-10-dev: include/d/std/stdio.d (and rest of std/*) missing on PowerPC (eg. ppc64el) architectures only

[Matija Nalis <mnalis-debianbug@voyager.hr>]

Package: libgphobos-10-dev
Version: 10.2.1-3
Severity: normal
X-Debbugs-Cc: mnalis-debianbug@voyager.hr

Dear Maintainer,

   * What led up to the situation?

after installing "gdc" and its dependencies on ppc64el, trying to compile my 
D program having "import std.stdio;" fails with error.
(in this case causing sid FTBFS of https://packages.debian.org/sid/ironseed on ppc64el architecture)

   * What exactly did you do (or not do) that was effective (or
     ineffective)?

I've tried to find a missing file. 
On other architectures, libgphobos-10-dev contains that file, eg.:

./usr/lib/gcc/x86_64-linux-gnu/10/include/d/std/stdio.d
./usr/lib/gcc/arm-linux-gnueabi/10/include/d/std/stdio.d
./usr/lib/gcc/s390x-linux-gnu/10/include/d/std/stdio.d

etc.

but on ppc64el whole following directory is missing:
./usr/lib/gcc/powerpc64le-linux-gnu/10/include/d/std/

The problem seems to be the same on all PowerPC architectures, eg. missing files in:
 - libgphobos-10-dev_10.2.1-3_ppc64el.deb
 - libgphobos-10-dev_10.2.1-1_ppc64el.deb
 - libgphobos-11-dev_11-20201222-1_ppc64el.deb
 - libgphobos-10-dev-ppc64el-cross_10.2.1-1cross1_all.deb
 - libgphobos-10-dev-ppc64-cross_10.2.1-1cross1_all.deb
 - libgphobos-10-dev-powerpc-cross_10.2.1-1cross1_all.deb

(std/stdio.d missing in that architecture, but present in others)
libgphobos-9-dev did not contain ppc* architectures on 
http://ftp.debian.org/debian/pool/main/g/gcc-9/, so I did not test further back.

   * What was the outcome of this action?

On ppc64el architecture, build fails with following error:

 gdc -g -o Data_Generators/makedata/logmake Data_Generators/makedata/logmake.d Data_Generators/makedata/data.d
 Data_Generators/makedata/logmake.d:26:8: error: module stdio is in file 'std/stdio.d' which cannot be read
    26 | import std.stdio;
       |        ^
 import path[0] = /usr/lib/gcc/powerpc64le-linux-gnu/10/include/d
 make: *** [Makefile:147: Data_Generators/makedata/logmake] Error 1


   * What outcome did you expect instead?

Finding a std/stdio.d file, resulting in successful compilation.


-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: ppc64el (ppc64le)

Kernel: Linux 5.2.0-0.bpo.2-amd64 (SMP w/2 CPU threads)
Locale: LANG=C, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /bin/dash
Init: unable to detect

Versions of packages libgphobos-10-dev depends on:
ii  gcc-10-base  10.2.1-3
ii  libgphobos1  10.2.1-3
ii  zlib1g-dev   1:1.2.11.dfsg-2

libgphobos-10-dev recommends no packages.

libgphobos-10-dev suggests no packages.

-- no debconf information