Allow for older kernels without hooks

At present, we still support <2020-10-01.
josephwright · Jan 23, 2024 · 8d3b7da · 8d3b7da
1 parent 132a9c5
commit 8d3b7da
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/siunitx-print.dtx b/siunitx-print.dtx
@@ -344,8 +344,10 @@
 % Color support is always required; to avoid a potential clash we delay to
 % the start of the document.
 %    \begin{macrocode}
-\hook_gput_code:nnn { begindocument / before } { siunitx }
-  { \RequirePackage { color } }
+\cs_if_exist:NTF \hook_gput_code:nnn
+  { \hook_gput_code:nnn { begindocument / before } { siunitx } }
+  { \AtBeginDocument }
+    { \RequirePackage { color } }
 %    \end{macrocode}
 %
 %   Required variants.