CI: wrapping command to make syntax happy

Author: bsipocz

tox.ini

@@ -63,7 +63,7 @@ commands =
     buildhtml: bash -c "find tutorials -name '*md' | grep -f ignore_testing | sort | uniq > ignore_execute; if [ -s ignore_execute ]; then cat ignore_execute | xargs -n 1 sed -i -e 's|name: python3|name: python3\nskip_execution: true|g';fi"
 
     # Status check is a workaround until https://github.com/jupyter-book/mystmd/issues/2113 is fixed
-    buildhtml: jupyter-book build --execute --html 2>&1 | tee /tmp/mystbuild.log
+    buildhtml: bash -c "jupyter-book build --execute --html 2>&1 | tee /tmp/mystbuild.log"
     buildhtml: bash -c "if grep -q 'Traceback .most recent call last.' /tmp/mystbuild.log; then exit 1; fi"
     buildhtml: bash -c "rm _build/html/*thebe*.js"