caff doesn't work with OpenPGP smartcards

[Robin Sheat]

I try to sign some keys:

$ caff 0xKEYID
[INFO] Importing key 0xKEYID from your normal GnuPGHome.
[INFO] fetching keys, this will take a while...
[INFO] Sign the following keys according to your policy, then exit gpg with 'save' after signing each key
gpg --homedir=/home/robin/.caff/gnupghome --secret-keyring /home/robin/.gnupg/secring.gpg --no-auto-check-trustdb --trust-model=always --edit 0xLONGKEYID sign
gpg (GnuPG) 1.4.12; Copyright (C) 2012 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

[...snip key details...]

Really sign all user IDs? (y/N) y

[...these errors don't look like problems, they're from keys I'm not using for this anyway...]

gpg: error checking usability status of 768B8765
gpg: sleutel 768B8765: geheime sleutel zonder publiek deel - overgeslagen
gpg: error checking usability status of 776DB663
gpg: sleutel 776DB663: geheime sleutel zonder publiek deel - overgeslagen
gpg: error checking usability status of A99CEB6D
gpg: sleutel A99CEB6D: geheime sleutel zonder publiek deel - overgeslagen
gpg: error checking usability status of 7DB96E4D
gpg: sleutel 7DB96E4D: geheime sleutel zonder publiek deel - overgeslagen
gpg: error checking usability status of A2E41F10
gpg: sleutel A2E41F10: geheime sleutel zonder publiek deel - overgeslagen

[...snip key details again ...]

Weet u zeker dat U deze sleutel wilt ondertekenen met Uw sleutel
 “Robin Sheat <email address hidden>” (F8713BDF)

Really sign? (y/N) y
gpg: pcsc_list_readers failed: unknown PC/SC error code (0x8010002e)
gpg: kaartlezer is niet beschikbaar
gpg: ondertekenen is mislukt: general error
gpg: ondertekenen is mislukt: general error

However, if I do it myself from the same command line:

$ gpg --sign-key 0xKEYID

[... snip key details ...]

Weet u zeker dat U deze sleutel wilt ondertekenen met Uw sleutel
 “Robin Sheat <email address hidden>” (F8713BDF)

Really sign? (y/N) y

$

...and it all worked.

So it seems that something in the GPG environment that caff sets up is breaking the access to the smartcard daemon, or something along those lines.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: signing-party 1.1.4-1
ProcVersionSignature: Ubuntu 3.8.0-30.44-generic 3.8.13.6
Uname: Linux 3.8.0-30-generic x86_64
ApportVersion: 2.9.2-0ubuntu8.3
Architecture: amd64
Date: Wed Oct 9 13:41:04 2013
MarkForUpload: True
SourcePackage: signing-party
UpgradeStatus: Upgraded to raring on 2013-06-10 (120 days ago)