Assertion failure when precompiling Images

[staticfloat]

While trying to track down a memory leak in Metalhead, I discovered the following assertion failure:

julia> using Images
[ Info: Precompiling Images [916415d5-f1e6-5110-898d-aaa5f9f070e0]
Assertion failed: (!jl_subtype((jl_value_t*)sig, (jl_value_t*)type)), function check_ambiguous_visitor, file /Users/sabae/src/julia/src/gf.c, line 1189.

signal (6): Abort trap: 6
in expression starting at /Users/sabae/.julia/packages/Images/3bPWU/src/Images.jl:46
__pthread_kill at /usr/lib/system/libsystem_kernel.dylib (unknown line)
Allocations: 3702182 (Pool: 3701803; Big: 379); GC: 5
ERROR: Failed to precompile Images [916415d5-f1e6-5110-898d-aaa5f9f070e0] to /Users/sabae/.julia/compiled/v1.1/Images/H8Vxc.ji.
Stacktrace:
 [1] error(::String) at ./error.jl:33
 [2] macro expansion at ./logging.jl:313 [inlined]
 [3] compilecache(::Base.PkgId, ::String) at ./loading.jl:1190
 [4] macro expansion at ./logging.jl:311 [inlined]
 [5] _require(::Base.PkgId) at ./loading.jl:947
 [6] require(::Base.PkgId) at ./loading.jl:858
 [7] macro expansion at ./logging.jl:311 [inlined]
 [8] require(::Module, ::Symbol) at ./loading.jl:840

julia> versioninfo()
Julia Version 1.1.0-DEV.376
Commit 23bf90292e (2018-10-04 16:18 UTC)
DEBUG build
Platform Info:
  OS: macOS (x86_64-apple-darwin17.7.0)
  CPU: Intel(R) Core(TM) i7-8559U CPU @ 2.70GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-6.0.1 (ORCJIT, skylake)

[JeffBezanson]

Should check whether #29539 fixes it.

[staticfloat]

Nope, it doesn't. Just checked on e13b2852e2 and the same thing happened.

[JeffBezanson]

If you need to debug stuff in the meantime, you should just comment out the assertion. This tends to mean that two methods have very similar signatures (and are possibly even ambiguous), such that we might call the wrong one but it doesn't matter much in practice.

[mbauman]

I'm hitting this with 1.2-rc1 and JuliaDB (well, StructArrays):

julia> using JuliaDB
[ Info: Precompiling JuliaDB [a93385a2-3734-596a-9a66-3cfbb77141e6]
Assertion failed: (!jl_subtype((jl_value_t*)sig, (jl_value_t*)type)), function check_ambiguous_visitor, file /Users/julia/buildbot/worker/package_macos64/build/src/gf.c, line 1109.

signal (6): Abort trap: 6
in expression starting at /Users/mbauman/.julia/packages/StructArrays/Du4zZ/src/structarray.jl:67
__pthread_kill at /usr/lib/system/libsystem_kernel.dylib (unknown line)
Allocations: 665194 (Pool: 664979; Big: 215); GC: 0
ERROR: LoadError: Failed to precompile StructArrays [09ab397b-f2b6-538f-b94a-2f83cf4a842a] to /Users/mbauman/.julia/compiled/v1.2/StructArrays/jRMFC.ji.