Sorry if this question has already been answered.
I noticed that if the challenges are successfully completed, but the client fails for some other reason before the certs are saved to the
./archive directory, the certificates are actually issued and committed (as can be seen at https://crt.sh/?caid=7395), but are not available to the user.
As the server seems not to know that the client has failed, and because certs are actually committed, if the user tries to repeat the process enough times (for example if the client continues to fail for the same reason), he will soon hit the maximum allowed number of certificates per domain (5 in 7 days), without obtaining even one.
Could it be a good idea to check if there are some ‘pending’ certificates (e.g. that were issued but not saved client-side) and notify the user of that, to avoid the problems described above?