Julia v1.11 (all RCs) breaks package SolidStateDetectors (not caught by PkgEval due to timeout)

[oschulz]

The Julia v1.11 (RC1, RC2 and RC3) breaks SolidStateDetectors.

On Julia v1.11 is looks like the SolidStateDetectors field calculation setup causes the compiler to stall. On v1.10 all is fine, and we never had this problem before with SolidStateDetectors and older Julia versions.

Nanosoldier PkgEval didn't catch this, because SolidStateDetectors tests take fairly long and exceed the time limit, so the fact that it stalls completely now on v1.11 didn't make a difference there ...

Sorry for reporting this so late - we've tried to track down what is happening, or at least build a compact MWE, but we've dug into it again and again over weeks now and, and this is still the shortest reproducible demonstration of the problem that @fhagemann and me could come up with:

With a fresh, empty deport, install the latest release of SolidStateDetectors

(@v1.11) pkg> add SolidStateDetectors@0.9.9

This runs fine in a REPL, still:

using SolidStateDetectors
using SolidStateDetectors: PotentialCalculationSetup

sim = Simulation(SSD_examples[:InvertedCoax])
SolidStateDetectors.apply_initial_state!(sim, ElectricPotential)

# runs:
pcs = PotentialCalculationSetup(
    sim.detector, sim.electric_potential.grid, sim.medium, sim.electric_potential.data, sim.imp_scale.data
);

But as soon as the PotentialCalculationSetup ctor is put in a function, the compiler seems to stall infinitely long:

function test_pcs(sim::Simulation)
    PotentialCalculationSetup(
        sim.detector, sim.electric_potential.grid, sim.medium, sim.electric_potential.data, sim.imp_scale.data
    )
end
# runs on Julia v1.10, stalls on v1.11-rc1 to v1.11-rc3:
test_pcs(sim)

Tested on

julia> versioninfo()
Julia Version 1.11.0-rc3
Commit 616e45539db (2024-08-26 15:46 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 20 × 13th Gen Intel(R) Core(TM) i9-13900H
  WORD_SIZE: 64
  LLVM: libLLVM-16.0.6 (ORCJIT, goldmont)
Threads: 6 default, 0 interactive, 3 GC (on 20 virtual cores)