Use feature flag in docs.rs env because of proc-macro-error crate failures

waku-sys/Cargo.toml

@@ -30,6 +30,10 @@ exclude = [
 [lib]
 crate-type = ["rlib"]
 
+# Prevent building Waku go when building docs on docs.rs.
+[package.metadata.docs.rs]
+features = ["private-docs-rs"]
+
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 [dependencies]
 

waku-sys/build.rs

@@ -95,7 +95,8 @@ fn main() {
     let project_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
 
     // Skip building go waku binary if in Rust Docs environment.
-    if std::env::var("DOCS_RS").is_err() {
+    // TODO: use DOCS_RS env var (proc-macro failure needs to be resolved).
+    if !cfg!(feature = "private-docs-rs") {
         let go_bin = get_go_bin();
         build_go_waku_lib(&go_bin, &project_dir);
     }