In debugging #32923, I found that while it is possible to do a guix build in WSL on a aarch64 machine, the resulting zip files did not match the build on x86_64. The binaries within the zip files matched, and it appears the non-determinism comes from zip including the file permissions. This is presumably because the WSL build occurs on a NTFS drive which handles file permissions differently from other unix file systems.
Diffoscope output:
--- x86_64-zipinfo 2025-07-09 23:52:39.650231781 -0700
+++ aarch64-zipinfo 2025-07-09 23:52:45.010145329 -0700
@@ -1,27 +1,27 @@
-Archive: ../../../guix-build-ea5d2bb98598/output/x86_64-w64-mingw32/bitcoin-ea5d2bb98598-win64-unsigned.zip
+Archive: bitcoin-ea5d2bb98598-win64-unsigned.zip
Zip file size: 45922845 bytes, number of entries: 24
-drwxr-xr-x 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/
-drwxr-xr-x 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/
--rwxr-xr-x 3.0 unx 2235411 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-cli.exe
--rwxr-xr-x 3.0 unx 40257059 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-qt.exe
--rwxr-xr-x 3.0 unx 4107283 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-tx.exe
--rwxr-xr-x 3.0 unx 1935891 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-util.exe
--rwxr-xr-x 3.0 unx 8202259 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-wallet.exe
--rwxr-xr-x 3.0 unx 1216019 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin.exe
--rwxr-xr-x 3.0 unx 14261779 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoind.exe
--rwxr-xr-x 3.0 unx 25802259 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/test_bitcoin.exe
--rw-r--r-- 3.0 unx 126 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bitcoin.conf
--rw-r--r-- 3.0 unx 846 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/readme.txt
-drwxr-xr-x 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/
-drwxr-xr-x 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/
-drwxr-xr-x 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/
--rw-r--r-- 3.0 unx 214 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-cli.1
--rw-r--r-- 3.0 unx 211 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-qt.1
--rw-r--r-- 3.0 unx 211 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-tx.1
--rw-r--r-- 3.0 unx 217 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-util.1
--rw-r--r-- 3.0 unx 223 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-wallet.1
--rw-r--r-- 3.0 unx 205 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoind.1
-drwxr-xr-x 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/rpcauth/
--rw-r--r-- 3.0 unx 453 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/rpcauth/README.md
--rwxr-xr-x 3.0 unx 1764 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/rpcauth/rpcauth.py
+drwxrwxrwx 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/
+drwxrwxrwx 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/
+-rwxrwxrwx 3.0 unx 2235411 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-cli.exe
+-rwxrwxrwx 3.0 unx 40257059 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-qt.exe
+-rwxrwxrwx 3.0 unx 4107283 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-tx.exe
+-rwxrwxrwx 3.0 unx 1935891 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-util.exe
+-rwxrwxrwx 3.0 unx 8202259 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-wallet.exe
+-rwxrwxrwx 3.0 unx 1216019 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin.exe
+-rwxrwxrwx 3.0 unx 14261779 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoind.exe
+-rwxrwxrwx 3.0 unx 25802259 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/test_bitcoin.exe
+-rwxrwxrwx 3.0 unx 126 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bitcoin.conf
+-rwxrwxrwx 3.0 unx 846 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/readme.txt
+drwxrwxrwx 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/
+drwxrwxrwx 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/
+drwxrwxrwx 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/
+-rwxrwxrwx 3.0 unx 214 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-cli.1
+-rwxrwxrwx 3.0 unx 211 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-qt.1
+-rwxrwxrwx 3.0 unx 211 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-tx.1
+-rwxrwxrwx 3.0 unx 217 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-util.1
+-rwxrwxrwx 3.0 unx 223 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-wallet.1
+-rwxrwxrwx 3.0 unx 205 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoind.1
+drwxrwxrwx 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/rpcauth/
+-rwxrwxrwx 3.0 unx 453 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/rpcauth/README.md
+-rwxrwxrwx 3.0 unx 1764 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/rpcauth/rpcauth.py