Add debugging information.

Author: johnedmonds

rust/private/rustc.bzl

@@ -118,6 +118,11 @@ def collect_deps(deps, toolchain):
             staticlibs = [l for l in libs.to_list() if l.basename.endswith(toolchain.staticlib_ext)]
             transitive_dylibs = depset(transitive = [transitive_dylibs, depset(dylibs)])
             transitive_staticlibs = depset(transitive = [transitive_staticlibs, depset(staticlibs)])
+            print("All libs: " + str(libs.to_list()))
+            print("Looking for dylibs (libs with extension: " + toolchain.dylib_ext + ")")
+            print("Looking for static libs (libs with extension:" + toolchain.staticlib_ext + ")")
+            print("Transitive dylibs: " + str(transitive_dylibs.to_list()))
+            print("Transitive staticlibs: " + str(transitive_staticlibs.to_list()))
         else:
             fail("rust targets can only depend on rust_library, rust_*_library or cc_library targets." + str(dep), "deps")
 
@@ -316,6 +321,9 @@ def rustc_compile_action(
         mnemonic = "Rustc",
         progress_message = "Compiling Rust {} {} ({} files)".format(crate_info.type, ctx.label.name, len(crate_info.srcs)),
     )
+
+    print("Runfiles (dylibs): " + str(dep_info.transitive_dylibs.to_list()))
+    print("Runfiles (data): " + str(getattr(ctx.files, "data", [])))
     runfiles = ctx.runfiles(
         files = dep_info.transitive_dylibs.to_list() + getattr(ctx.files, "data", []),
         collect_data = True,