Given following log snippets, their explanation, and nothing else, explain what failure, if any, occurred during build of this package.

  Snippets are in a format of [X] : [Y], where [X] is a log snippet, and [Y] is the explanation.

  Snippets are delimited with '================'.

  Drawing on information from all snippets, provide a concise explanation of the issue and recommend a solution.

  Explanation of the issue, and recommended solution, should take a handful of sentences.

  Snippets:

  [[headless_shell:458/35389] COPY default_for_rust_host_build_tools/obj/build/rust/std/libadler.rlib default_for_rust_host_build_tools/prebuilt_rustc_sysroot/lib/rustlib/x86_64-unknown-linux-gnu/lib/libadler.rlib
FAILED: default_for_rust_host_build_tools/prebuilt_rustc_sysroot/lib/rustlib/x86_64-unknown-linux-gnu/lib/libadler.rlib 
ln -f default_for_rust_host_build_tools/obj/build/rust/std/libadler.rlib default_for_rust_host_build_tools/prebuilt_rustc_sysroot/lib/rustlib/x86_64-unknown-linux-gnu/lib/libadler.rlib 2>/dev/null || (rm -rf default_for_rust_host_build_tools/prebuilt_rustc_sysroot/lib/rustlib/x86_64-unknown-linux-gnu/lib/libadler.rlib && cp -af default_for_rust_host_build_tools/obj/build/rust/std/libadler.rlib default_for_rust_host_build_tools/prebuilt_rustc_sysroot/lib/rustlib/x86_64-unknown-linux-gnu/lib/libadler.rlib)
cp: cannot stat 'default_for_rust_host_build_tools/obj/build/rust/std/libadler.rlib': No such file or directory]: [This relevant error message saying that 'COPY default_for_rust_host_build_tools/obj/build/rust/std/libadler.rlib' failed because libadler.rlib is not found.]
=============
[DEBUG util.py:459:  [ 92/568] rust-0:1.86.0-1.fc43.x86_64   100% |  51.2 MiB/s |  27.1 MiB |  00m01s]: [Possible clue for debugging the issue locally with rpmbuild]
=============
[Patch #315 (chromium-134-rust-libadler2.patch):
+ echo 'Patch #315 (chromium-134-rust-libadler2.patch):']: [diff -up chromium-134.0.6998.23/build/rust/std/BUILD.gn.than chromium-134.0.6998.23/build/rust/std/BUILD.gn
--- chromium-134.0.6998.23/build/rust/std/BUILD.gn.than 2025-02-24 09:47:57.560506410 +0100
+++ chromium-134.0.6998.23/build/rust/std/BUILD.gn      2025-02-24 09:48:02.335676712 +0100
@@ -89,7 +89,7 @@ if (toolchain_has_rust) {
     # These are no longer present in the Windows toolchain.
     stdlib_files += [
       "addr2line",
-      "adler2",
+      "adler",
       "gimli",
       "libc",
       "memchr"

This patch file changed adler2 to adler and  was the cause for the build failure]

Issue: The build failed because there's new rust-1.86 which replaces adler to adler2 in the fedora 42 and rawhide. 
Resolution: Added condition to apply chromium-134-rust-libadler2.patch only when having rust-1.85 or older.