LaTeX warnings during the build

In a typical build, over 50% of the lines of the log is taken by LaTeX warnings. Examples:

LaTeX Warning: Reference `ghci:ghc-flag--fexternal-interpreter' on page 62 unde
fined on input line 5013.

LaTeX Warning: Reference `using:options-order' on page 70 undefined on input li
ne 5490.

LaTeX Warning: Label `exts/strict:bang-patterns' multiply defined.

Either those are genuine issues that should be fixed, or the LaTeX build should be made less verbose.