When importing a secret key without a passphrase, I notice that gnupg 2.1.16 is
much slower than previous versions. The attached test script demonstrates the
problem, which I bisected to commit 4473db1ef24031ff4e26c9a9de95dbe898ed2b97.
When run with versions before that commit, gpg --import completes more or less
instantly. After that version, it takes ~12 seconds.
Running with --debug-level guru shows that most of the time is spent on:
gpg: DBG: chan_4 <- S PROGRESS need_entropy X 120 120
It looks like 4473db1ef added a 100ms pause when we ask for entropy. I wonder if
this is triggering more often than it should, as we otherwise seem to get enough
entropy instantly.