[gentoo-dev] [PATCH] acct-user.eclass: improve error message when usermod fails

[Mike Gilbert <floppym@gentoo.org>]

usermod refuses to update the home directory for a user with running
processes. Output a more helpful message and avoid calling die for this.

For other usermod failures, output stderr as an eerror message and die.

Example output:

 * Failed to update user portage
 * This user currently has one or more running processes.
 * Please update this user manually with the following command:
 *   usermod '--comment' 'System user; portage' '--home' '/var/lib/portage/home' '--shell' '/bin/bash' '--gid' 'portage' '--groups' '' portage

Bug: https://bugs.gentoo.org/888189
Signed-off-by: Mike Gilbert <floppym@gentoo.org>
---
 eclass/acct-user.eclass | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/eclass/acct-user.eclass b/eclass/acct-user.eclass
index f8a51ebf9c6b..88d7d354c8e6 100644
--- a/eclass/acct-user.eclass
+++ b/eclass/acct-user.eclass
@@ -432,12 +432,30 @@ acct-user_pkg_postinst() {
 	fi
 
 	elog "Updating user ${ACCT_USER_NAME}"
-	if ! usermod "${opts[@]}" "${ACCT_USER_NAME}" 2>"${T}/usermod-error.log"; then
-		# usermod outputs a warning if unlocking the account would result in an
-		# empty password. Hide stderr in a text file and display it if usermod
-		# fails.
+	# usermod outputs a warning if unlocking the account would result in an
+	# empty password. Hide stderr in a text file and display it if usermod fails.
+	usermod "${opts[@]}" "${ACCT_USER_NAME}" 2>"${T}/usermod-error.log"
+	local status=$?
+	if [[ ${status} -ne 0 ]]; then
 		cat "${T}/usermod-error.log" >&2
-		die "usermod failed"
+		if [[ ${status} -eq 8 ]]; then
+			# usermod refused to update the home directory
+			# for a uid with active processes.
+			eerror "Failed to update user ${ACCT_USER_NAME}"
+			eerror "This user currently has one or more running processes."
+			eerror "Please update this user manually with the following command:"
+
+			# Surround opts with quotes.
+			# With bash-5 (EAPI 8), we can use "${opts[@]@Q}" instead.
+			local q="'"
+			local optsq=( "${opts[@]/#/$q}" )
+			optsq=( "${optsq[@]/%/$q}" )
+
+			eerror "  usermod ${optsq[@]} ${ACCT_USER_NAME}"
+		else
+			eerror "$(<"${T}/usermod-error.log")"
+			die "usermod failed"
+		fi
 	fi
 }
 
-- 
2.41.0