I've been unable to use my gnuk usb smartcard token with gnupg on
GuixSD, and it appears this is because scdaemon is built without libusb
support:

      $ gpg --card-status
      gpg: selecting openpgp failed: No such device
      gpg: OpenPGP card not available: No such device

Attached is a patch that gets scdaemon working for me and a gnuk...

Unfortunately, enabling libusb causes one of the tets to hang
indefinitely:

      PASS: tests/openpgp/decrypt-session-key.scm
      Checking unwrapping the encryption.
          > encsig-2-keys-3 encsig-2-keys-4 <
      PASS: tests/openpgp/decrypt-unwrap-verify.scm
      Checking signing with the default hash algorithm
          >

So far, I've only been able to get it to work by disabling the
tests... so it's obviously not a good idea to enable without further
troubleshooting.

Another option might be to use pcsc-lite and ccid, but I had even less
luck getting that to work.


live well,
  vagrant


diff --git a/gnu/packages/gnupg.scm b/gnu/packages/gnupg.scm
index f397482ab..0e9e72784 100644
--- a/gnu/packages/gnupg.scm
+++ b/gnu/packages/gnupg.scm
@@ -39,6 +39,7 @@
   #:use-module (gnu packages curl)
   #:use-module (gnu packages crypto)
   #:use-module (gnu packages emacs)
+  #:use-module (gnu packages libusb)
   #:use-module (gnu packages openldap)
   #:use-module (gnu packages perl)
   #:use-module (gnu packages perl-check)
@@ -232,6 +233,7 @@ compatible to GNU Pth.")
        ("libgcrypt" ,libgcrypt)
        ("libgpg-error" ,libgpg-error)
        ("libksba" ,libksba)
+       ("libusb" ,libusb)
        ("npth" ,npth)
        ("openldap" ,openldap)
        ("pcsc-lite" ,pcsc-lite)
@@ -246,12 +248,17 @@ compatible to GNU Pth.")
                           "--enable-all-tests")
       #:phases
       (modify-phases %standard-phases
+	;; (delete 'check)
         (add-before 'configure 'patch-paths
           (lambda* (#:key inputs #:allow-other-keys)
             (substitute* "scd/scdaemon.c"
               (("\"(libpcsclite\\.so[^\"]*)\"" _ name)
                (string-append "\"" (assoc-ref inputs "pcsc-lite")
                               "/lib/" name "\"")))
+            (substitute* "configure"
+              (("/usr/include/libusb-1.0")
+               (string-append (assoc-ref inputs "libusb")
+                              "/include/libusb-1.0")))
             #t))
         (add-after 'build 'patch-scheme-tests
           (lambda _