Don't build tier one targets by default

Author: jyn514

src/config.rs

@@ -106,7 +106,7 @@ impl Config {
             local_docker_image: maybe_env("DOCS_RS_LOCAL_DOCKER_IMAGE")?,
             toolchain: env("CRATESFYI_TOOLCHAIN", "nightly".to_string())?,
             build_cpu_limit: maybe_env("DOCS_RS_BUILD_CPU_LIMIT")?,
-            include_default_targets: env("DOCSRS_INCLUDE_DEFAULT_TARGETS", true)?,
+            include_default_targets: env("DOCSRS_INCLUDE_DEFAULT_TARGETS", false)?,
             disable_memory_limit: env("DOCSRS_DISABLE_MEMORY_LIMIT", false)?,
         })
     }

src/docbuilder/rustwide_builder.rs

@@ -762,7 +762,10 @@ mod tests {
             let version = DUMMY_CRATE_VERSION;
             let default_target = "x86_64-unknown-linux-gnu";
 
-            assert_eq!(env.config().include_default_targets, true);
+            env.override_config(|config| {
+                assert_eq!(config.include_default_targets, false);
+                config.include_default_targets = true;
+            });
 
             let mut builder = RustwideBuilder::init(env).unwrap();
             builder