Bug

On 32-bit Julia (UInt == UInt32), loading SymbolicUtils fails at precompile time:

julia> using SymbolicUtils
ERROR: LoadError: InexactError: trunc(UInt32, 0x8b4142913acd1c23)
 [6] hash_bsimpl(...)  @ SymbolicUtils hashconsing.jl:467
...
[22] top-level scope  @ SymbolicUtils/src/SymbolicUtils.jl:178  # @compile_workload

Fires inside the @compile_workload block, so every downstream package fails to precompile on 32-bit too.

Root cause

src/hashconsing.jl:310 declares FNTYPE_SEED as a raw UInt64 literal, unlike SYM_SALT/DIV_SALT on lines 225–226 which correctly coerce with % UInt:

const FNTYPE_SEED = 0x8b414291138f6c45          # line 310 — bug
const SYM_SALT    = 0x4de7d7c66d41da43 % UInt   # line 225 — correct

On 32-bit, FNTYPE_SEED is UInt64. Its only use (line 351) is hash(...)::UInt ⊻ FNTYPE_SEED — the ::UInt only constrains the inner hash call, so the XOR widens the result to UInt64, which then fails to fit back into a ::UInt field.

Sanity check: 0x8b414291138f6c45 ⊻ 0x8b4142913acd1c23 = 0x0000000029427066 — upper 32 bits unchanged, which is exactly what XOR'ing a zero-extended UInt32 into a UInt64 looks like.

Fix

-const FNTYPE_SEED = 0x8b414291138f6c45
+const FNTYPE_SEED = 0x8b414291138f6c45 % UInt

No-op on 64-bit; truncates the constant to UInt32 on 32-bit. Happy to send a PR.

Versions

SymbolicUtils 4.24.2 (also 4.21.0); Julia 1.12 stable and nightly; Linux x86 and Windows x86. Not reproduced on any x64 target. Hit initially in CI for ReversePropagation.jl.

CI note

This regression escaped because ci.yml tests only ubuntu-latest × x64 — no arch key in the matrix, so 32-bit targets are never exercised. Adding arch: [x64, x86] (with a macOS-x86 exclude) would have caught it.