C API: fix documentation build

package.nix

@@ -5,6 +5,7 @@
 , autoreconfHook
 , aws-sdk-cpp
 , boehmgc
+, buildPackages
 , nlohmann_json
 , bison
 , boost
@@ -91,9 +92,10 @@
 # - readline
 , readlineFlavor ? if stdenv.hostPlatform.isWindows then "readline" else "editline"
 
-# Whether to build the internal API docs, can be done separately from
+# Whether to build the internal/external API docs, can be done separately from
 # everything else.
 , enableInternalAPIDocs ? false
+, enableExternalAPIDocs ? false
 
 # Whether to install unit tests. This is useful when cross compiling
 # since we cannot run them natively during the build, but can do so
@@ -199,7 +201,7 @@ in {
     ++ lib.optional doBuild "dev"
     # If we are doing just build or just docs, the one thing will use
     # "out". We only need additional outputs if we are doing both.
-    ++ lib.optional (doBuild && (enableManual || enableInternalAPIDocs)) "doc"
+    ++ lib.optional (doBuild && (enableManual || enableInternalAPIDocs || enableExternalAPIDocs)) "doc"
     ++ lib.optional installUnitTests "check";
 
   nativeBuildInputs = [
@@ -221,7 +223,7 @@ in {
   ] ++ lib.optionals (doInstallCheck || enableManual) [
     jq # Also for custom mdBook preprocessor.
   ] ++ lib.optional stdenv.hostPlatform.isLinux util-linux
-    ++ lib.optional enableInternalAPIDocs doxygen
+    ++ lib.optional (enableInternalAPIDocs || enableExternalAPIDocs) doxygen
   ;
 
   buildInputs = lib.optionals doBuild [
@@ -285,6 +287,7 @@ in {
     (lib.enableFeature buildUnitTests "unit-tests")
     (lib.enableFeature doInstallCheck "functional-tests")
     (lib.enableFeature enableInternalAPIDocs "internal-api-docs")
+    (lib.enableFeature enableExternalAPIDocs "external-api-docs")
     (lib.enableFeature enableManual "doc-gen")
     (lib.enableFeature enableGC "gc")
     (lib.enableFeature enableMarkdown "markdown")
@@ -309,7 +312,8 @@ in {
   makeFlags = "profiledir=$(out)/etc/profile.d PRECOMPILE_HEADERS=1";
 
   installTargets = lib.optional doBuild "install"
-    ++ lib.optional enableInternalAPIDocs "internal-api-html";
+    ++ lib.optional enableInternalAPIDocs "internal-api-html"
+    ++ lib.optional enableExternalAPIDocs "external-api-html";
 
   installFlags = "sysconfdir=$(out)/etc";
 
@@ -336,6 +340,10 @@ in {
   '' + lib.optionalString enableInternalAPIDocs ''
     mkdir -p ''${!outputDoc}/nix-support
     echo "doc internal-api-docs $out/share/doc/nix/internal-api/html" >> ''${!outputDoc}/nix-support/hydra-build-products
+  ''
+    + lib.optionalString enableExternalAPIDocs ''
+    mkdir -p ''${!outputDoc}/nix-support
+    echo "doc external-api-docs $out/share/doc/nix/external-api/html" >> ''${!outputDoc}/nix-support/hydra-build-products
   '';
 
   # So the check output gets links for DLLs in the out output.