--- /dev/null
+++ b/gnu/packages/patches/julia-SOURCE_DATE_EPOCH-mtime.patch
@@ -0,0 +1,22 @@
+Fix one of upstream non-determinism, tracked here:
+
+https://github.com/JuliaLang/julia/issues/34115
+https://github.com/JuliaLang/julia/issues/25900
+
+
+Patch by Nicoló Balzarotti <nicolo@nixo.xyz>.
+
+--- a/base/loading.jl
++++ b/base/loading.jl
+@@ -807,7 +807,10 @@
+         path = normpath(joinpath(dirname(prev), _path))
+     end
+     if _track_dependencies[]
+-        push!(_require_dependencies, (mod, path, mtime(path)))
++          push!(_require_dependencies,
++                (mod, path,
++                 haskey(ENV, "SOURCE_DATE_EPOCH") ?
++                 parse(Float64, ENV["SOURCE_DATE_EPOCH"]) : mtime(path)))
+     end
+     return path, prev
+ end
-- 
2.26.0