tl;dr - how do I get git to use gpg2 to sign things? I'm using gpg2 (so no agent options are configured but an agent is running) which is configured w/ a Nitrokey (Pro if it matters):
% git commit -m "Initial." gits/bash-libs (master ⚡) localhost gpg: detected reader `Nitrokey Nitrokey Pro (000034670000000000000000) 00 00' gpg: pcsc_connect failed: sharing violation (0x8010000b) gpg: apdu_send_simple(0) failed: locking failed Please insert the card and hit return or enter 'c' to cancel: gpg: pcsc_connect failed: sharing violation (0x8010000b) gpg: pcsc_connect failed: sharing violation (0x8010000b) gpg: apdu_send_simple(0) failed: locking failed Please insert the card and hit return or enter 'c' to cancel: c gpg: selecting openpgp failed: general error gpg: signing failed: general error gpg: signing failed: general error error: gpg failed to sign the data fatal: failed to write commit object This works with gpg and ssh: % touch foo ~ localhost % gpg2 --sign foo ~ localhost gpg: using "846FF490" as default secret key for signing % cat foo* ~ localhost -----BEGIN PGP MESSAGE----- Version: GnuPG v2 owEBuQFG/pANAwAKAYwdY7SEb/SQAcsJYgNmb29ZqxfviQGcBAABCgAGBQJZqxfv AAoJEIwdY7SEb/SQAcEL/jonw+HymnlmfebtEwlvfx2Gl1Sbuw0xWWPpQ2Dtjljz HtpD+LWczjpOSMTHFNK9xPR2kcs1WNY+mO8M45QI7iDgFkKRzaxEqeNUJkoyF/+I 81VMmXDQMXFs4+8jy00b+UxTdvwdXaHMsOtu+6YCtmCR5Bzohg07ADsnXnGGn3Sd WTjVMzV6Dlh8LRF+coGJ8JuErBsRAI6vdNgJRVHYBULGNXci4uF/4a+58uiTL4/U PvC4ruXCNxCKi89nMERhwlnOvglseX3TDR5ldrc4Hzb+pLsj/l6N4sBW0Zmb8UcE 9BG3WjOs4eZvnLmk5XHrwisD2CXuHvyWMl0yH7LTrg+m4Itj0PJ4Px4H9E5t/zfs C1vcB/okcigeIyXnO06um02a5oZAYOKadB+6NRnBjULz5GvP2yxj/AO1VPmZprpt budMuHZcA0zNE3uBmcnQY5+1tdkyTrlTxsL58lQrn/U3wvgah3AXMEvjRGqbYWHj jDikQVJ7ESoevNqlfLPj8Q== =hV6v -----END PGP MESSAGE----- However, if I try this w/ the old gpg: % gpg -ae -o foo.gpg foo ~ localhost % gpg -d foo.gpg ~ localhost gpg: detected reader `Nitrokey Nitrokey Pro (000034670000000000000000) 00 00' gpg: pcsc_connect failed: sharing violation (0x8010000b) gpg: apdu_send_simple(0) failed: locking failed Please insert the card and hit return or enter 'c' to cancel: c gpg: selecting openpgp failed: general error gpg: encrypted with 3072-bit RSA key, ID 41826CFB, created 2017-03-13 "Shawn Wilson <ag4ve...@gmail.com>" gpg: public key decryption failed: general error gpg: decryption failed: secret key not available % gpg2 -d foo.gpg ~ localhost gpg: encrypted with 3072-bit RSA key, ID E27FA0B841826CFB, created 2017-03-13 "Shawn Wilson <ag4ve...@gmail.com>" foo (yeah I added data to the file) And just to prove basic competency checking: % git config --global -l | grep sign ~ localhost user.signingkey=846FF490 filter.gitconfig-rmuser.clean=sed -e "s/^\( *email =\).*/\1 <email address>/" -e "s/^\( *name =\).*/\1 <real name>/" -e "s/^\( *signingkey =\).*/\1 <gpg key>/" filter.gitconfig-rmuser.smudge=egrep "^ *(email|name|signingkey) = " commit.gpgsign=true