Fix Doxygen workflow (XRPLF#4372)

.github/workflows/doxygen.yml

@@ -1,4 +1,5 @@
 name: Build and publish Doxygen documentation
+# To test this workflow, push your changes to your fork's `develop` branch.
 on:
   push:
     branches:
@@ -11,12 +12,18 @@ jobs:
       image: docker://rippleci/rippled-ci-builder:2944b78d22db
     steps:
       - name: checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
+      - name: check environment
+        run: |
+          echo ${PATH} | tr ':' '\n'
+          cmake --version
+          doxygen --version
+          env
       - name: build
         run: |
           mkdir build
           cd build
-          cmake -DBoost_NO_BOOST_CMAKE=ON ..
+          cmake -Donly_docs=TRUE ..
           cmake --build . --target docs --parallel $(nproc)
       - name: publish
         uses: peaceiris/actions-gh-pages@v3

.github/workflows/nix.yml

@@ -74,7 +74,7 @@ jobs:
         run: |
           mkdir ${build_dir}
           cd ${build_dir}
-          conan install .. --build missing --settings build_type=${{ matrix.configuration }} --profile:build default --profile:host default
+          conan install .. --build missing --settings build_type=${{ matrix.configuration }}
       - name: configure
         run: |
           cd ${build_dir}

Builds/CMake/RippledDocs.cmake

@@ -2,9 +2,9 @@
    docs target (optional)
 #]===================================================================]
 
-# Early return if the `docs` directory is missing,
-# e.g. when we are building a Conan package.
-if(NOT EXISTS docs)
+option(with_docs "Include the docs target?" FALSE)
+
+if(NOT (with_docs OR only_docs))
   return()
 endif()
 

CMakeLists.txt

@@ -58,6 +58,12 @@ endif ()
 include(RippledCompiler)
 include(RippledInterface)
 
+option(only_docs "Include only the docs target?" FALSE)
+include(RippledDocs)
+if(only_docs)
+  return()
+endif()
+
 ###
 
 include(deps/Boost)
@@ -119,5 +125,4 @@ include(RippledCore)
 include(RippledInstall)
 include(RippledCov)
 include(RippledMultiConfig)
-include(RippledDocs)
 include(RippledValidatorKeys)