treewide: more accurate pandoc/shellcheck availability checks

The actual problem here is that there is no GHC bootstrap tarball for
RISC-V or LoongArch, so the right thing to check here is whether the
platform being used to build GHC has a bootstrap tarball available for
it.  This way, we'll do the right thing in all cases where such a
tarball isn't available, not just riscv64 and loongarch64, without
having to resort to tryEval, which could be hiding all sorts of
problems.

Since we need to refer to (unspliced) buildPackages.pandoc and
buildPackages.shellcheck in the conditionals, I've opted to remove the
pandoc and shellcheck inputs that would be spliced in
nativeBuildInputs and use buildPackages explicitly there as well, to
avoid confusingly having two different instances of the same package
around.

pkgs/build-support/trivial-builders/default.nix

@@ -367,17 +367,14 @@ rec {
         '';
 
       checkPhase =
-        # GHC (=> shellcheck) isn't supported on some platforms (such as risc-v)
-        # but we still want to use writeShellApplication on those platforms
         let
-          shellcheckSupported =
-            lib.meta.availableOn stdenv.buildPlatform shellcheck-minimal.compiler
-            && (builtins.tryEval shellcheck-minimal.compiler.outPath).success;
           excludeFlags = lib.optionals (excludeShellChecks != [ ]) [
             "--exclude"
             (lib.concatStringsSep "," excludeShellChecks)
           ];
-          shellcheckCommand = lib.optionalString shellcheckSupported ''
+          # GHC (=> shellcheck) isn't supported on some platforms (such as risc-v)
+          # but we still want to use writeShellApplication on those platforms
+          shellcheckCommand = lib.optionalString shellcheck-minimal.compiler.bootstrapAvailable ''
             # use shellcheck which does not include docs
             # pandoc takes long to build and documentation isn't needed for just running the cli
             ${lib.getExe shellcheck-minimal} ${

pkgs/by-name/fl/flac/package.nix

@@ -6,11 +6,11 @@
   lib,
   libogg,
   nix-update-script,
-  pandoc,
+  buildPackages,
   pkg-config,
   stdenv,
   versionCheckHook,
-  enableManpages ? !stdenv.buildPlatform.isRiscV64 && !stdenv.buildPlatform.isLoongArch64,
+  enableManpages ? buildPackages.pandoc.compiler.bootstrapAvailable,
 }:
 stdenv.mkDerivation (finalAttrs: {
   pname = "flac";
@@ -30,7 +30,7 @@ stdenv.mkDerivation (finalAttrs: {
     doxygen
     graphviz
     pkg-config
-  ] ++ lib.optional enableManpages pandoc;
+  ] ++ lib.optional enableManpages buildPackages.pandoc;
 
   buildInputs = [ libogg ];
 

pkgs/by-name/ni/nixos-firewall-tool/package.nix

@@ -3,7 +3,7 @@
   lib,
   bash,
   installShellFiles,
-  shellcheck-minimal,
+  buildPackages,
 }:
 
 stdenvNoCC.mkDerivation {
@@ -14,7 +14,7 @@ stdenvNoCC.mkDerivation {
   strictDeps = true;
   buildInputs = [ bash ];
   nativeBuildInputs = [ installShellFiles ];
-  nativeCheckInputs = [ shellcheck-minimal ];
+  nativeCheckInputs = [ buildPackages.shellcheck-minimal ];
 
   postPatch = ''
     patchShebangs --host nixos-firewall-tool
@@ -26,10 +26,7 @@ stdenvNoCC.mkDerivation {
     installShellCompletion nixos-firewall-tool.{bash,fish}
   '';
 
-  # Skip shellcheck if GHC is not available, see writeShellApplication.
-  doCheck =
-    lib.meta.availableOn stdenvNoCC.buildPlatform shellcheck-minimal.compiler
-    && (builtins.tryEval shellcheck-minimal.compiler.outPath).success;
+  doCheck = buildPackages.shellcheck-minimal.compiler.bootstrapAvailable;
   checkPhase = ''
     shellcheck nixos-firewall-tool
   '';

pkgs/development/libraries/gssdp/1.6.nix

@@ -7,8 +7,8 @@
   pkg-config,
   gobject-introspection,
   vala,
-  enableManpages ? !stdenv.buildPlatform.isLoongArch64 && !stdenv.buildPlatform.isRiscV64,
-  pandoc,
+  buildPackages,
+  enableManpages ? buildPackages.pandoc.compiler.bootstrapAvailable,
   gi-docgen,
   python3,
   libsoup_3,
@@ -44,7 +44,7 @@ stdenv.mkDerivation rec {
     vala
     gi-docgen
     python3
-  ] ++ lib.optionals enableManpages [ pandoc ];
+  ] ++ lib.optionals enableManpages [ buildPackages.pandoc ];
 
   buildInputs = [
     libsoup_3

pkgs/development/libraries/nuspell/default.nix

@@ -3,11 +3,11 @@
   stdenv,
   fetchFromGitHub,
   cmake,
-  pandoc,
+  buildPackages,
   pkg-config,
   icu,
   catch2_3,
-  enableManpages ? !stdenv.buildPlatform.isRiscV64 && !stdenv.buildPlatform.isLoongArch64,
+  enableManpages ? buildPackages.pandoc.compiler.bootstrapAvailable,
 }:
 
 stdenv.mkDerivation rec {
@@ -27,7 +27,7 @@ stdenv.mkDerivation rec {
       pkg-config
     ]
     ++ lib.optionals enableManpages [
-      pandoc
+      buildPackages.pandoc
     ];
 
   buildInputs = [ catch2_3 ];