apt-key does not print "Key fingerprint =" in front of fingerprints

[Jon Gorrono]

A common idiom for checking fingerprints for keys begins with:
' apt-key fingerprint $key|grep fingerprint|...'
... this works up to thru jessie at least.. in zesty apt-key gives a 'warning' but produces no output.

"Warning: apt-key output should not be parsed (stdout is not a terminal)"
If the lack of output is intended and is meant to be a proscription, it is overreaching at best. A warning makes perfect sense.

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: apt 1.4
ProcVersionSignature: Ubuntu 4.10.0-32.36-generic 4.10.17
Uname: Linux 4.10.0-32-generic x86_64
ApportVersion: 2.20.4-0ubuntu4.5
Architecture: amd64
Date: Sun Sep 10 01:23:46 2017
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: apt
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Julian Andres Klode (juliank)]

Works for me:

 docker run --rm -it ubuntu:zesty sh -c 'apt-key fingerprint | grep Ubu'
Warning: apt-key output should not be parsed (stdout is not a terminal)
uid [ unknown] Ubuntu Archive Automatic Signing Key (2012) <email address hidden>
uid [ unknown] Ubuntu CD Image Automatic Signing Key (2012) <email address hidden>

[Julian Andres Klode (juliank)]

Does it output anything to your terminal?

[Julian Andres Klode (juliank)]

Notably, the word fingerprint does not appear anywhere in the output, so if you search for literally that, then that's your problem.

[Julian Andres Klode (juliank)]

gpg changed the output format later on to remove "Key fingerprint=".

jak@jak-x230:~/Projects/Debian/apt:master$ docker run --rm -it ubuntu:xenial sh -c 'apt-key fingerprint'
/etc/apt/trusted.gpg
--------------------
pub 1024D/437D05B5 2004-09-12
      Key fingerprint = 6302 39CC 130E 1A7F D81A 27B1 4097 6EAF 437D 05B5
uid Ubuntu Archive Automatic Signing Key <email address hidden>
sub 2048g/79164387 2004-09-12

pub 4096R/C0B21F32 2012-05-11
      Key fingerprint = 790B C727 7767 219C 42C8 6F93 3B4F E6AC C0B2 1F32
uid Ubuntu Archive Automatic Signing Key (2012) <email address hidden>

pub 4096R/EFE21092 2012-05-11
      Key fingerprint = 8439 38DF 228D 22F7 B374 2BC0 D94A A3F0 EFE2 1092
uid Ubuntu CD Image Automatic Signing Key (2012) <email address hidden>

pub 1024D/FBB75451 2004-12-30
      Key fingerprint = C598 6B4F 1257 FFA8 6632 CBA7 4618 1433 FBB7 5451
uid Ubuntu CD Image Automatic Signing Key <email address hidden>

jak@jak-x230:~/Projects/Debian/apt:master$ docker run --rm -it ubuntu:zesty sh -c 'apt-key fingerprint'
/etc/apt/trusted.gpg.d/ubuntu-keyring-2012-archive.gpg
------------------------------------------------------
pub rsa4096 2012-05-11 [SC]
      790B C727 7767 219C 42C8 6F93 3B4F E6AC C0B2 1F32
uid [ unknown] Ubuntu Archive Automatic Signing Key (2012) <email address hidden>

/etc/apt/trusted.gpg.d/ubuntu-keyring-2012-cdimage.gpg
------------------------------------------------------
pub rsa4096 2012-05-11 [SC]
      8439 38DF 228D 22F7 B374 2BC0 D94A A3F0 EFE2 1092
uid [ unknown] Ubuntu CD Image Automatic Signing Key (2012) <email address hidden>

[Julian Andres Klode (juliank)]

Or maybe we did, but I'm not sure where.