diff --git a/boehmgc-coroutine-sp-fallback.diff b/boehmgc-coroutine-sp-fallback.diff
index 5066d8278..2afbe9671 100644
--- a/boehmgc-coroutine-sp-fallback.diff
+++ b/boehmgc-coroutine-sp-fallback.diff
@@ -59,12 +59,18 @@ index b5d71e62..aed7b0bf 100644
      GC_bool found_me = FALSE;
      size_t nthreads = 0;
      int i;
-@@ -851,6 +853,31 @@ GC_INNER void GC_push_all_stacks(void)
+@@ -851,6 +853,37 @@ GC_INNER void GC_push_all_stacks(void)
            hi = p->altstack + p->altstack_size;
            /* FIXME: Need to scan the normal stack too, but how ? */
            /* FIXME: Assume stack grows down */
 +        } else {
-+          if (pthread_getattr_np(p->id, &pattr)) {
++#ifdef HAVE_PTHREAD_ATTR_GET_NP
++          if (!pthread_attr_init(&pattr)
++              || !pthread_attr_get_np(p->id, &pattr))
++#else /* HAVE_PTHREAD_GETATTR_NP */
++          if (pthread_getattr_np(p->id, &pattr))
++#endif
++          {
 +            ABORT("GC_push_all_stacks: pthread_getattr_np failed!");
 +          }
 +          if (pthread_attr_getstacksize(&pattr, &stack_limit)) {
diff --git a/flake.nix b/flake.nix
index 230bb6031..0722d4a5b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -25,7 +25,10 @@
       darwinSystems = [ "x86_64-darwin" "aarch64-darwin" ];
       systems = linuxSystems ++ darwinSystems;
 
-      crossSystems = [ "armv6l-linux" "armv7l-linux" ];
+      crossSystems = [
+        "armv6l-linux" "armv7l-linux"
+        "x86_64-freebsd13" "x86_64-netbsd"
+      ];
 
       stdenvs = [ "gccStdenv" "clangStdenv" "clang11Stdenv" "stdenv" "libcxxStdenv" "ccacheStdenv" ];
 
@@ -86,7 +89,14 @@
       nixpkgsFor = forAllSystems
         (system: let
           make-pkgs = crossSystem: stdenv: import nixpkgs {
-            inherit system crossSystem;
+            localSystem = {
+              inherit system;
+            };
+            crossSystem = if crossSystem == null then null else {
+              system = crossSystem;
+            } // lib.optionalAttrs (crossSystem == "x86_64-freebsd13") {
+              useLLVM = true;
+            };
             overlays = [
               (overlayFor (p: p.${stdenv}))
             ];
@@ -172,9 +182,9 @@
             libarchive
             boost
             lowdown-nix
+            libsodium
           ]
           ++ lib.optionals stdenv.isLinux [libseccomp]
-          ++ lib.optional (stdenv.isLinux || stdenv.isDarwin) libsodium
           ++ lib.optional stdenv.hostPlatform.isx86_64 libcpuid;
 
         checkDeps = [
@@ -725,6 +735,9 @@
 
       devShells = let
         makeShell = pkgs: stdenv:
+          let
+            canRunInstalled = stdenv.buildPlatform.canExecute stdenv.hostPlatform;
+          in
           with commonDeps { inherit pkgs; };
           stdenv.mkDerivation {
             name = "nix";
@@ -732,13 +745,18 @@
             outputs = [ "out" "dev" "doc" ];
 
             nativeBuildInputs = nativeBuildDeps
-                                ++ (lib.optionals stdenv.cc.isClang [ pkgs.bear pkgs.clang-tools ]);
+              ++ lib.optional stdenv.cc.isClang pkgs.buildPackages.bear
+              ++ lib.optional
+                (stdenv.cc.isClang && stdenv.hostPlatform == stdenv.buildPlatform)
+                pkgs.buildPackages.clang-tools
+              ;
 
             buildInputs = buildDeps ++ propagatedDeps
               ++ awsDeps ++ checkDeps ++ internalApiDocsDeps;
 
             configureFlags = configureFlags
-              ++ testConfigureFlags ++ internalApiDocsConfigureFlags;
+              ++ testConfigureFlags ++ internalApiDocsConfigureFlags
+              ++ lib.optional (!canRunInstalled) "--disable-doc-gen";
 
             enableParallelBuilding = true;
 
diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc
index 56f47a4ac..9c2ad039a 100644
--- a/src/libmain/shared.cc
+++ b/src/libmain/shared.cc
@@ -379,9 +379,9 @@ RunPager::RunPager()
     });
 
     pid.setKillSignal(SIGINT);
-    stdout = fcntl(STDOUT_FILENO, F_DUPFD_CLOEXEC, 0);
+    std_out = fcntl(STDOUT_FILENO, F_DUPFD_CLOEXEC, 0);
     if (dup2(toPager.writeSide.get(), STDOUT_FILENO) == -1)
-        throw SysError("dupping stdout");
+        throw SysError("dupping standard output");
 }
 
 
@@ -390,7 +390,7 @@ RunPager::~RunPager()
     try {
         if (pid != -1) {
             std::cout.flush();
-            dup2(stdout, STDOUT_FILENO);
+            dup2(std_out, STDOUT_FILENO);
             pid.wait();
         }
     } catch (...) {
diff --git a/src/libmain/shared.hh b/src/libmain/shared.hh
index 7a9e83c6c..9415be78a 100644
--- a/src/libmain/shared.hh
+++ b/src/libmain/shared.hh
@@ -85,8 +85,9 @@ struct LegacyArgs : public MixCommonArgs
 void showManPage(const std::string & name);
 
 /**
- * The constructor of this class starts a pager if stdout is a
- * terminal and $PAGER is set. Stdout is redirected to the pager.
+ * The constructor of this class starts a pager if standard output is a
+ * terminal and $PAGER is set. Standard output is redirected to the
+ * pager.
  */
 class RunPager
 {
@@ -96,7 +97,7 @@ public:
 
 private:
     Pid pid;
-    int stdout;
+    int std_out;
 };
 
 extern volatile ::sig_atomic_t blockInt;