policy towards abi-dumper backwards and forward compatibility

[nmav]

abi-dumper is easy to use and combine with abi-compliance-checker and has it been used in several projects to track backwards compatibility. The way it was been used in the projects I was involved is keep a dump of old libraries, and then compare the current build against them.

Unfortunately at 1.1 abi-dumper broke compatibility with older files.

That caused the following issues.

1. The abi-compliance-checker suddently stopped working within updates in distributions [0]
2. Dumps of old libraries are no longer useful, and even worse, most of the times it is impossible to re-create (for the libidn2 library which I was trying the first versions are notoriously hard to compile on modern systems) - see [1]
3. abi-dumper and abi-compliance-checker can now be used only if the dump is generated in the same system as the compliance-checker is run.

(3) is the worst of them as it makes relying to abi-dumper for continuous testing purposes impossible. It is very hard to guarrantee indefinitely that the system where these files are generated is exactly the same as the one abi-compliance-checker is run (as I said old libraries cannot be compiled in any arbitrary system, I have to compile them on the old systems they were intended to be run).

The question is what are the best practices for running these tools for that purpose? Would it make sense to have a minimal baseline format which will be portable and be always supported?

[0]. https://bugzilla.redhat.com/show_bug.cgi?id=1502214
[1]. https://gitlab.com/libidn/libidn2/issues/42