base: workaround s6 bug when /bin is a symlink

base/Dockerfile

@@ -19,7 +19,13 @@ RUN <<-EOF
     apt-dpkg-wrap apt-get update
     apt-dpkg-wrap apt-get install -y apt-transport-https apt-utils ca-certificates gnupg lsb-release wget
     wget -qO /usr/bin/tpl https://github.com/jitsi/tpl/releases/download/v1.0.4/tpl-linux-${TPL_ARCH}
-    wget -qO - https://github.com/just-containers/s6-overlay/releases/download/v1.22.1.0/s6-overlay-${S6_ARCH}.tar.gz | tar hxfz - -C /
+    wget -qO /tmp/s6.tar.gz https://github.com/just-containers/s6-overlay/releases/download/v1.22.1.0/s6-overlay-${S6_ARCH}.tar.gz
+    mkdir /tmp/s6
+    tar xfz /tmp/s6.tar.gz -C /tmp/s6
+    tar hxfz /tmp/s6.tar.gz -C /
+    rm -f /usr/bin/execlineb
+    cp /tmp/s6/bin/execlineb /usr/bin/
+    rm -rf /tmp/s6*
     wget -qO - https://download.jitsi.org/jitsi-key.gpg.key | gpg --dearmour > /etc/apt/trusted.gpg.d/jitsi.gpg
     echo "deb https://download.jitsi.org $JITSI_RELEASE/" > /etc/apt/sources.list.d/jitsi.list
     echo "deb http://ftp.debian.org/debian $(lsb_release -sc)-backports main" > /etc/apt/sources.list.d/backports.list