'make checkabi' abigail assertion

[tonyhutter]

System information

Type	Version/Name
Distribution Name	Ubuntu
Distribution Version	18.04
Kernel Version
Architecture	x86-64
OpenZFS Version	master

Describe the problem you're observing

I hit this on the make checkabi github runner:

make[2]: Leaving directory '/home/ubuntu/zfs/lib/libuutil'
make[2]: Entering directory '/home/ubuntu/zfs/lib/libzfs_core'
for lib in libzfs_core.la ; do \
        abidiff --no-unreferenced-symbols \
            --headers-dir1 ../../include \
            --suppressions ${lib%.la}.suppr \
            ${lib%.la}.abi .libs/${lib%.la}.so ; \
done
abidiff: ../../src/abg-reader.cc:4616: abigail::ir::union_decl_sptr abigail::xml_reader::build_union_decl(abigail::xml_reader::read_context&, xmlNodePtr, bool): Assertion `previous_definition->get_name() == name' failed.
/bin/bash: line 1: 30907 Aborted                 (core dumped) abidiff --no-unreferenced-symbols --headers-dir1 ../../include --suppressions ${lib%.la}.suppr ${lib%.la}.abi .libs/${lib%.la}.so
Makefile:1094: recipe for target 'checkabi' failed
make[2]: *** [checkabi] Error 134
make[2]: Leaving directory '/home/ubuntu/zfs/lib/libzfs_core'
Makefile:975: recipe for target 'checkabi' failed
make[1]: *** [checkabi] Error 2
make[1]: Leaving directory '/home/ubuntu/zfs/lib'
Makefile:1513: recipe for target 'checkabi' failed

It seems to have been encountered before: #12355 (comment)

I also hit the same problem on ubuntu 20.04. It's fixed in Ubuntu 21.04, which runs the newer abigail 1.8.2, but unfortunately github does not have a ubuntu 21.04 runner.

Describe how to reproduce the problem

make checkabi

Include any warning/errors/backtraces from the system logs

[gmelikov]

Closed in #12529