Downgrade CI to Debian 8 for glibc 2.19

Closes #1656

Author: nhooyr

ci/container/Dockerfile

@@ -1,4 +1,9 @@
-FROM debian
+FROM debian:8
+
+# We need latest jq from debian buster for date support.
+COPY buster.list /etc/apt/sources.list.d
+RUN mkdir -p /etc/apt/preferences.d
+COPY buster.pref /etc/apt/preferences.d
 
 RUN apt-get update
 
@@ -27,10 +32,11 @@ RUN apt-get install -y gettext-base
 RUN apt-get install -y jq git rsync
 
 # Installs shellcheck.
-RUN curl -sSL https://github.com/koalaman/shellcheck/releases/download/v0.7.1/shellcheck-v0.7.1.linux.$(uname -m).tar.xz | \
-    tar -xJ && \
-    mv shellcheck*/shellcheck /usr/local/bin && \
-    rm -R shellcheck*
+# Unfortunately coredumps on debian:8
+#RUN curl -sSL https://github.com/koalaman/shellcheck/releases/download/v0.7.1/shellcheck-v0.7.1.linux.$(uname -m).tar.xz | \
+#    tar -xJ && \
+#    mv shellcheck*/shellcheck /usr/local/bin && \
+#    rm -R shellcheck*
 
 # Install Go dependencies
 RUN ARCH="$(dpkg --print-architecture)" && \

ci/container/buster.list

@@ -0,0 +1,6 @@
+# deb http://snapshot.debian.org/archive/debian/20200514T145000Z buster main
+deb http://deb.debian.org/debian buster main
+# deb http://snapshot.debian.org/archive/debian-security/20200514T145000Z buster/updates main
+deb http://security.debian.org/debian-security buster/updates main
+# deb http://snapshot.debian.org/archive/debian/20200514T145000Z buster-updates main
+deb http://deb.debian.org/debian buster-updates main

ci/container/buster.pref

@@ -0,0 +1,3 @@
+Package: jq
+Pin: release a=buster
+Pin-Priority: 900

ci/dev/lint.sh

@@ -7,7 +7,10 @@ main() {
   eslint --max-warnings=0 --fix $(git ls-files "*.ts" "*.tsx" "*.js")
   stylelint $(git ls-files "*.css")
   tsc --noEmit
-  shellcheck -e SC2046,SC2164,SC2154 $(git ls-files "*.sh")
+  # See comment in ./ci/container/Dockerfile
+  if [[ ! ${CI-} ]]; then
+    shellcheck -e SC2046,SC2164,SC2154 $(git ls-files "*.sh")
+  fi
 }
 
 main "$@"