"ubuntu-bug linux" command on PowerPC will ask for authentication

On Bionic, when reporting bug with "ubuntu-bug linux" command in a terminal, you will be asked to enter password on a PowerPC:

$ ubuntu-bug linux

*** Collecting problem information

The collected information can be sent to the developers to improve the
application. This might take a few minutes.
................tar: Removing leading `/' from member names
==== AUTHENTICATING FOR com.ubuntu.apport.root-info ===
Authentication is required to collect system information for this problem report
Authenticating as: Ubuntu (ubuntu)
Password:

But with other arch like AMD64, you won't be asked for the authentication.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: apport 2.20.9-0ubuntu7.5
ProcVersionSignature: User Name 4.15.0-43.46-generic 4.15.18
Uname: Linux 4.15.0-43-generic ppc64le
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: ppc64el
Date: Thu Jan 24 07:07:36 2019
PackageArchitecture: all
ProcLoadAvg: 882.90 268.29 93.65 1281/2696 24907
ProcLocks:
 1: POSIX ADVISORY WRITE 3876 00:17:569 0 EOF
 2: FLOCK ADVISORY WRITE 3556 00:17:497 0 EOF
 3: FLOCK ADVISORY WRITE 4090 00:17:596 0 EOF
 4: POSIX ADVISORY WRITE 3955 00:17:571 0 EOF
 5: POSIX ADVISORY WRITE 1823 00:17:348 0 EOF
ProcSwaps:
 Filename Type Size Used Priority
 /swap.img file 8388544 0 -2
ProcVersion: Linux version 4.15.0-43-generic (buildd@bos02-ppc64el-020) (gcc version 7.3.0 (User Name 7.3.0-16ubuntu3)) #46-User Name SMP Thu Dec 6 14:43:28 UTC 2018
SourcePackage: apport
UpgradeStatus: No upgrade log present (probably fresh install)
VarLogDump_list: total 0
cpu_cores: Number of cores present = 40
cpu_coreson: Number of cores online = 40
cpu_smt: SMT=4