Sphinx allows for definitions of command-line options using .. option <name> and references to those options via :option:<name>. However, it looks like there is no scoping of these options by default, meaning that links can end up pointing to incorrect documents. See for example the llvm-mca document, which contains references to -o that point to a different document. What's worse is that these links appear to be non-deterministic in which one is picked (on my machine, some references end up pointing to opt, whereas on the live docs, they point to llvm-dwarfdump, for example).
The fix is to add the .. program <name> tag. This essentially namespaces the options (definitions and references) to the named program, ensuring that the links are kept correct.