import with opam 2.2 of an export file created with 2.1.2 fails

[Khady]

$ opam sw import ./opam-switch-export-20240424-111440.txt --sw=.
Switch initialisation failed: clean up? ('n' will leave the switch partially installed)
[y/n] y
Fatal error:
Invalid_argument("Wrong padding")

The file was generated with

opam switch export --full opam-switch-export-20240424-111440.txt

I'll see if I can share the file without leaking details.

[kit-ty-kate]

I had access to the file and the "Wrong padding" exception here is raised from the base64 library.

There seems to be an incompatibility between the base64 encoder from extlib (< 1.7.8) that was used before and the decoder from the base64 library (that is now used in 2.2 by 4d8229e). I'm having a deeper look

[kit-ty-kate]

#5943 should fix this