diff --git a/.travis.yml b/.travis.yml
index 623d8b984908..3ece77a236cb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,8 @@
 version: ~> 1.0 # needed for imports
-
 import: scala/scala-dev:travis/default.yml
 
+dist: bionic  # for generating spec PDF; see #7432
+
 language: scala
 
 stages:
@@ -105,10 +106,19 @@ jobs:
           - gem install bundler
           - bundler --version
           - bundle install
+          # cribbed from https://github.com/SebastiaanKlippert/go-wkhtmltopdf/blob/master/.travis.yml
+          - sudo apt-get update
+          - sudo apt-get install -y build-essential xorg xfonts-75dpi libpng16-16 libssl1.1
+          - wget --quiet "https://github.com/wkhtmltopdf/packaging/releases/download/0.12.6-1/wkhtmltox_0.12.6-1.bionic_amd64.deb"
+          - sudo dpkg -i "wkhtmltox_0.12.6-1.bionic_amd64.deb"
+          - rm "wkhtmltox_0.12.6-1.bionic_amd64.deb"
         script:
           - set -e
           - (cd admin && ./init.sh)
           - bundle exec jekyll build -s spec/ -d build/spec
+          - export JEKYLL_ENV=spec-pdf
+          - bundle exec jekyll build -s spec/ -d build/spec-pdf
+          - ./scripts/generate-spec-pdf.sh
         after_success:
           - ./scripts/travis-publish-spec.sh
 
diff --git a/scripts/generate-spec-pdf.sh b/scripts/generate-spec-pdf.sh
old mode 100644
new mode 100755
index 38f94ac1b24f..c49d0d39d1a6
--- a/scripts/generate-spec-pdf.sh
+++ b/scripts/generate-spec-pdf.sh
@@ -1,5 +1,8 @@
 #!/usr/bin/env bash
 
+set -e
+set -v
+
 # NOTES:
 # "toc"                     -> treated just like another page, its location can be changed
 # "--window-status loaded"  -> when window.status is set to "loaded", wkhtmltopdf knows js is loaded
@@ -8,15 +11,29 @@ THIS_SCRIPT_DIR=$(dirname $0)
 ROOT_DIR=$THIS_SCRIPT_DIR/..
 SPEC_SRC_DIR=$ROOT_DIR/spec
 SPEC_BUILD_DIR=$ROOT_DIR/build/spec
+SPEC_PDF_BUILD_DIR=$ROOT_DIR/build/spec-pdf
+PDF=$SPEC_BUILD_DIR/spec.pdf
+
+mkdir -p $SPEC_PDF_BUILD_DIR
+
 
-WKHTML_OPTS='--print-media-type --window-status loaded --footer-center [page] --javascript-delay 1000 --footer-font-name "Luxi Sans"'
+WKHTML_OPTS='--print-media-type --window-status loaded --javascript-delay 1000 --load-error-handling ignore --enable-local-file-access  --footer-center [page] --footer-font-name "Luxi Sans"'
 WKHTML_TOC="toc --xsl-style-sheet $SPEC_SRC_DIR/spec-toc.xslt"
 
-# exclude index.html, prepend SPEC_BUILD_DIR path
-HTML_FILES=$(ls $SPEC_BUILD_DIR -I 'index.html' | grep '\.html$' | while read line; do echo "$SPEC_BUILD_DIR/$line"; done)
+# exclude index.html, prepend SPEC_PDF_BUILD_DIR path
+HTML_FILES=$(ls $SPEC_PDF_BUILD_DIR | grep -vx 'index.html' | grep '\.html$' | while read line; do echo "$SPEC_PDF_BUILD_DIR/$line"; done)
 
-echo "Making Spec.pdf with HTML files: "
-echo $SPEC_BUILD_DIR/index.html $HTML_FILES
+echo "Making spec.pdf with HTML files: "
+echo $SPEC_PDF_BUILD_DIR/index.html $HTML_FILES
 
 # first goes index.html, then TOC, then rest
-wkhtmltopdf $WKHTML_OPTS $SPEC_BUILD_DIR/index.html $WKHTML_TOC $HTML_FILES $SPEC_BUILD_DIR/Spec.pdf
\ No newline at end of file
+rm -f $PDF
+wkhtmltopdf $WKHTML_OPTS $SPEC_PDF_BUILD_DIR/index.html $WKHTML_TOC $HTML_FILES $PDF || true
+
+# the '|| true' thing is because we get:
+#   Error: Failed to load http:/, with network status code 3 and http status code 0 - Host  not found
+#   Warning: Failed loading page http: (ignored)
+# as long we have `--load-error-handling ignore` we still get a PDF, but we also get a nonzero exit code
+
+# fail if we didn't get a PDF file out
+if [ ! -f $PDF ] ; then exit 1 ; fi
diff --git a/spec/_layouts/default.yml b/spec/_layouts/default.yml
index 85dd08ac7e01..1de9b89d1dba 100644
--- a/spec/_layouts/default.yml
+++ b/spec/_layouts/default.yml
@@ -8,8 +8,7 @@
 
   <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.10.0/dist/katex.min.css" integrity="sha384-9eLZqc9ds8eNjO3TmqPeYcDj8n+Qfa4nuSiGYa6DjLNcv9BtN69ZIulL9+8CqC9Y" crossorigin="anonymous">
   <script defer src="https://cdn.jsdelivr.net/npm/katex@0.10.0/dist/katex.min.js" integrity="sha384-K3vbOmF2BtaVai+Qk37uypf7VrgBubhQreNQe9aGsz9lB63dIFiQVlJbr92dw2Lx" crossorigin="anonymous"></script>
-  <script defer src="https://cdn.jsdelivr.net/npm/katex@0.10.0/dist/contrib/auto-render.min.js" integrity="sha384-kmZOZB5ObwgQnS/DuDg6TScgOiWWBiVt0plIRkZCmE6rDZGrEOQeHM5PcHi+nyqe" crossorigin="anonymous"
-    onload="renderMathInElement(document.body);"></script>
+  <script defer src="https://cdn.jsdelivr.net/npm/katex@0.10.0/dist/contrib/auto-render.min.js" integrity="sha384-kmZOZB5ObwgQnS/DuDg6TScgOiWWBiVt0plIRkZCmE6rDZGrEOQeHM5PcHi+nyqe" crossorigin="anonymous"></script>
   
   <script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>
   <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/8.2/styles/default.min.css">
@@ -44,6 +43,7 @@
 {{ content }}
   </main>
 
+  <script>window.jekyllEnv = '{{jekyll.environment}}';</script>
   <script src="public/scripts/toc.js"></script>
   <script src="public/scripts/highlight.pack.js"></script>
   <script src="public/scripts/main.js"></script>
diff --git a/spec/public/scripts/main.js b/spec/public/scripts/main.js
index 51625189f4bf..9ade9c770f1e 100644
--- a/spec/public/scripts/main.js
+++ b/spec/public/scripts/main.js
@@ -27,16 +27,19 @@ function heading(i, heading, $heading) {
   }
 }
 
-$('#toc').toc(
-  {
-    'selectors': 'h1,h2,h3',
-    'smoothScrolling': false,
-    'chapter': currentChapter(),
-    'headerLevel': 1,
-    'headerCounts': [-1, currentChapter() - 1, 1, 1],
-    'headerText': heading
-  }
-);
+// ignore when using wkhtmltopdf, or it won't work...
+if(window.jekyllEnv !== 'spec-pdf') {
+  $('#toc').toc(
+    {
+      'selectors': 'h1,h2,h3',
+      'smoothScrolling': false,
+      'chapter': currentChapter(),
+      'headerLevel': 1,
+      'headerCounts': [-1, currentChapter() - 1, 1, 1],
+      'headerText': heading
+    }
+  );
+}
 
 // no language auto-detect so that EBNF isn't detected as scala
 hljs.configure({