Install sudo for elevated tests.

.github/workflows/docker.yaml

@@ -35,7 +35,7 @@ jobs:
       if: startsWith(matrix.container, 'alpine')
       run: |
         apk upgrade -U
-        apk add git curl bash gcc make m4 patch musl-dev linux-headers lddtree shadow openssh-client file unzip perl g++ musl-locales dejagnu
+        apk add git curl bash gcc make m4 patch musl-dev linux-headers lddtree shadow openssh-client file unzip perl g++ musl-locales dejagnu sudo
         apk del util-linux-dev
         curl --output /usr/bin/paxctl https://bin.chevah.com:20443/third-party-stuff/alpine/paxctl-3.12
         chmod +x /usr/bin/paxctl
@@ -44,7 +44,7 @@ jobs:
       if: startsWith(matrix.container, 'amazonlinux')
       run: |
         yum -y upgrade
-        yum -y install git-core gcc make m4 patch tar unzip perl perl-Test-Simple perl-IPC-Cmd xz gcc-c++ dejagnu bzip2
+        yum -y install git-core gcc make m4 patch tar unzip perl perl-Test-Simple perl-IPC-Cmd xz gcc-c++ dejagnu bzip2 sudo
         # To avoid linking against libdb and gdmb libraries on Amazon Linux 2.
         # Can't simply uninstall libdb-devel and gdmb-devel, they are required by perl-IPC-Cmd.
         rm -v /usr/include/libdb/db.h
@@ -57,7 +57,7 @@ jobs:
       run: |
         apt update
         apt --yes dist-upgrade
-        apt --yes install wget curl gcc make m4 patch openssh-client unzip git libtest-simple-perl xz-utils g++ dejagnu
+        apt --yes install wget curl gcc make m4 patch openssh-client unzip git libtest-simple-perl xz-utils g++ dejagnu sudo
 
     # actions/checkout doesn't work on Amazon Linux 2, requires glibc 2.27.
     - name: Clone repo independently