The build of the ET documentation should be tested as part of the automated build and test.
The documentation should be built nightly and automatically, but should not be build on HPC production systems. These often don't have latex etc. installed, and it is also not necessary to build the documentation there.
Indeed; it can be part of the ubuntu build VMs running under Jenkins. In fact, it was previously built, but a documentation build failure led to an overall build failure which stopped the tests from running, so rather than fixing that I removed it (I was probably focused on something else). I am considering having a separate build job which does not run the tests, but always does a full build, for the purpose of tracking warnings. The documentation build could be added to that.