GC error (probable corruption)

General Usage
1

I’m stuggling to reproduce a gc related error on Julia v0.7 and v1.0, Windows x86. (But notably, not Julia v0.6.)

The tests for GLPK.jl fail with the following error. (Here is the Appveyor log.)

Allocations: 2388187 (Pool: 2388000; Big: 187); GC: 12
GC error (probable corruption) :
!!! ERROR in jl_ -- ABORTING !!!
1474F020: Queued root: 0D2D6AD0 :: 0D000050 (bits: 3)
        of type Core.TypeName
1474F02C: Queued root: 0DD30E80 :: 0D000050 (bits: 3)
        of type Core.TypeName
... many more lines like this ...

We’re using the new Appveyor.jl script. For some reason, adding the following prior to - echo "%JL_TEST_SCRIPT%" results in the tests passing without deprecation warnings.
- C:\julia\bin\julia -e "VERSION >= v\"0.7-\" && (using Pkg; Pkg.add(\"LinQuadOptInterface\"); using LinQuadOptInterface)"
(LinQuadOptInterface is a dependency package.)

I’ve tried various things to reproduce this locally without success.

Any ideas what this is, where it might come from, or how to go about fixing?