ZSystems

Here's the exact error message with respect to the failing assertion:

[  398s] + gdmd -g -ofbin/dub -w -O -version=DubUseCurl -Isource -L-lcurl @build-files.txt
[  757s] 
[  990s] 
[ 1102s] Serializing composite type Flags!(BuildRequirement) which has no serializable fields
[ 1105s] Serializing composite type Flags!(BuildOption) which has no serializable fields
[ 1125s] source/dub/internal/dyaml/stdsumtype.d:2053:13: error: static assert:  "`handlers[0]` of type `template` never matches"
[ 1125s]  2053 |             static assert(matches[].canFind(hid),
[ 1125s]       |             ^
[ 1125s] source/dub/internal/dyaml/stdsumtype.d:1717:52: note: instantiated from here: 'matchImpl!(const(SumType!(NativePath, Version)))'
[ 1125s]  1717 |         return matchImpl!(Yes.exhaustive, handlers)(args);
[ 1125s]       |                                                    ^
[ 1125s] source/dub/commandline.d:2333:43: note: instantiated from here: 'match!(const(SumType!(NativePath, Version)))'
[ 1125s]  2333 |                                 ovr.target.match!(
[ 1125s]       |                                           ^
[ 1126s] 
[ 1226s] error: Bad exit status from /var/tmp/rpm-tmp.gk3KYx (%build)
[ 1226s] 
[ 1226s] RPM build errors:
[ 1226s]     Bad exit status from /var/tmp/rpm-tmp.gk3KYx (%build)
[ 1231s] [ 1202.218365][    T1] sysrq: Power Off
[ 1231s] [ 1202.333638][  T272] reboot: Power down
[ 1231s] 
[ 1231s] oshrauch failed "build dub.spec" at Thu Apr  6 12:02:16 UTC 2023.

Seems to be a rather general bug with regard to gdmd/gdc (and still occurs with GCC13, at least on s390x), according to:
dub GH issue 2577

Explanation concernining the related issue:

• We need a working D compiler (including its corresponding druntime library)
• So far, building dub has been tested only using gdc/gdmd (as this is currently the only available D compiler for s390x)

A SR für a new version of dub has been provided by another user: https://build.opensuse.org/request/show/1084000