I installed gnupg2 and several versions of pinentry.
When I try to use it with engmail on thunderbird, I don't get prompted
for a passphrase.

My engmail setup works with a standalone version of gnupg2.
it also used to work with cygwin gnupg1 (before engmail required gnupg2).

When I invoke gnupg2 from the command line:
xeon:/cygdrive/u:502: gpg2 --output fred.good --decrypt fred.gpg
gpg: encrypted with 4096-bit RSA key, ID A3791E7DD935A424, created
2013-03-21
      "Jeff Deifik <jeff@jeffunit.com>"
gpg: public key decryption failed: No such device or address
gpg: decryption failed: No secret key


I should get something like:

You need a passphrase to unlock the secret key for
user: "Blake (Executioner) <blake@cyb.org>"
1024-bit ELG-E key, ID 5C8CBD41, created 1999-06-04 (main key ID 9E98BC16)

Enter passphrase:

Enclosed is cygcheck.out