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:
0--- x86_64-zipinfo 2025-07-09 23:52:39.650231781 -0700
1+++ aarch64-zipinfo 2025-07-09 23:52:45.010145329 -0700
2@@ -1,27 +1,27 @@
3-Archive: ../../../guix-build-ea5d2bb98598/output/x86_64-w64-mingw32/bitcoin-ea5d2bb98598-win64-unsigned.zip
4+Archive: bitcoin-ea5d2bb98598-win64-unsigned.zip
5 Zip file size: 45922845 bytes, number of entries: 24
6-drwxr-xr-x 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/
7-drwxr-xr-x 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/
8--rwxr-xr-x 3.0 unx 2235411 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-cli.exe
9--rwxr-xr-x 3.0 unx 40257059 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-qt.exe
10--rwxr-xr-x 3.0 unx 4107283 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-tx.exe
11--rwxr-xr-x 3.0 unx 1935891 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-util.exe
12--rwxr-xr-x 3.0 unx 8202259 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-wallet.exe
13--rwxr-xr-x 3.0 unx 1216019 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin.exe
14--rwxr-xr-x 3.0 unx 14261779 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoind.exe
15--rwxr-xr-x 3.0 unx 25802259 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/test_bitcoin.exe
16--rw-r--r-- 3.0 unx 126 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bitcoin.conf
17--rw-r--r-- 3.0 unx 846 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/readme.txt
18-drwxr-xr-x 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/
19-drwxr-xr-x 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/
20-drwxr-xr-x 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/
21--rw-r--r-- 3.0 unx 214 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-cli.1
22--rw-r--r-- 3.0 unx 211 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-qt.1
23--rw-r--r-- 3.0 unx 211 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-tx.1
24--rw-r--r-- 3.0 unx 217 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-util.1
25--rw-r--r-- 3.0 unx 223 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-wallet.1
26--rw-r--r-- 3.0 unx 205 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoind.1
27-drwxr-xr-x 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/rpcauth/
28--rw-r--r-- 3.0 unx 453 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/rpcauth/README.md
29--rwxr-xr-x 3.0 unx 1764 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/rpcauth/rpcauth.py
30+drwxrwxrwx 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/
31+drwxrwxrwx 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/
32+-rwxrwxrwx 3.0 unx 2235411 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-cli.exe
33+-rwxrwxrwx 3.0 unx 40257059 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-qt.exe
34+-rwxrwxrwx 3.0 unx 4107283 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-tx.exe
35+-rwxrwxrwx 3.0 unx 1935891 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-util.exe
36+-rwxrwxrwx 3.0 unx 8202259 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin-wallet.exe
37+-rwxrwxrwx 3.0 unx 1216019 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoin.exe
38+-rwxrwxrwx 3.0 unx 14261779 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/bitcoind.exe
39+-rwxrwxrwx 3.0 unx 25802259 b- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bin/test_bitcoin.exe
40+-rwxrwxrwx 3.0 unx 126 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/bitcoin.conf
41+-rwxrwxrwx 3.0 unx 846 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/readme.txt
42+drwxrwxrwx 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/
43+drwxrwxrwx 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/
44+drwxrwxrwx 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/
45+-rwxrwxrwx 3.0 unx 214 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-cli.1
46+-rwxrwxrwx 3.0 unx 211 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-qt.1
47+-rwxrwxrwx 3.0 unx 211 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-tx.1
48+-rwxrwxrwx 3.0 unx 217 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-util.1
49+-rwxrwxrwx 3.0 unx 223 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoin-wallet.1
50+-rwxrwxrwx 3.0 unx 205 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/man/man1/bitcoind.1
51+drwxrwxrwx 3.0 unx 0 b- stor 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/rpcauth/
52+-rwxrwxrwx 3.0 unx 453 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/rpcauth/README.md
53+-rwxrwxrwx 3.0 unx 1764 t- defN 25-Jul-10 05:44 bitcoin-ea5d2bb98598/share/rpcauth/rpcauth.py