.PHONY: external-api-html
ifeq ($(internal_api_docs), yes)
$(docdir)/external-api/html/index.html $(docdir)/external-api/latex: $(d)/doxygen.cfg
mkdir -p $(docdir)/external-api
{ cat $< ; echo "OUTPUT_DIRECTORY=$(docdir)/external-api" ; } | doxygen -
# Generate the HTML API docs for Nix's unstable internal interfaces.
external-api-html: $(docdir)/external-api/html/index.html
else
# Make a nicer error message
external-api-html:
@echo "Internal API docs are disabled. Configure with '--enable-external-api-docs', or avoid calling 'make external-api-html'."
@exit 1
endif