Add ctypes 0.20.0

[yallop]

From CHANGES.md:

• Remove naked pointers from the Dl library
  Remove naked pointers from the Dl library. yallop/ocaml-ctypes#681

• Avoid running a full GC cycle on every FFI closure allocation
  avoid running a full GC cycle on every FFI closure allocation yallop/ocaml-ctypes#694

• Check output of brew ls --versions when detecting homebrew
  More rigorous testing for homebrew yallop/ocaml-ctypes#697

Thanks to Martin Kletzander (@nertpinx) and Arseniy Alekseyev (@aalekseyev) for contributions to this release.

[kit-ty-kate]

It looks like the naked pointer fix didn’t bring ocaml-multicore support:

# running test-raw
# ..
# Ran: 2 tests in: 0.00 seconds.
# OK
# running test-pointers
# ....................FF.....
# ==============================================================================
# Error: Pointer tests:21:returned globals (stubs).
# 
# File "/home/opam/.opam/4.12/.opam-switch/build/ctypes.0.20.0/_build/oUnit-Pointer tests-builder#00.log", line 89, characters 1-1:
# Error: Pointer tests:21:returned globals (stubs) (in the log).
# 
# Raised at OUnitAssert.assert_failure in file "src/lib/ounit2/advanced/oUnitAssert.ml", line 45, characters 2-27
# Called from OUnitRunner.run_one_test.(fun) in file "src/lib/ounit2/advanced/oUnitRunner.ml", line 83, characters 13-26
# 
# not equal
# ------------------------------------------------------------------------------
# ==============================================================================
# Error: Pointer tests:20:returned globals (foreign).
# 
# File "/home/opam/.opam/4.12/.opam-switch/build/ctypes.0.20.0/_build/oUnit-Pointer tests-builder#00.log", line 82, characters 1-1:
# Error: Pointer tests:20:returned globals (foreign) (in the log).
# 
# Raised at OUnitAssert.assert_failure in file "src/lib/ounit2/advanced/oUnitAssert.ml", line 45, characters 2-27
# Called from OUnitRunner.run_one_test.(fun) in file "src/lib/ounit2/advanced/oUnitRunner.ml", line 83, characters 13-26
# 
# not equal
# ------------------------------------------------------------------------------
# Ran: 27 tests in: 0.01 seconds.
# FAILED: Cases: 27 Tried: 27 Errors: 0 Failures: 2 Skip:  0 Todo: 0 Timeouts: 0.
# make: *** [Makefile.tests:1395: run-test-pointers] Error 1

Is that expected?

[yallop]

It's not expected; it's an issue with Multicore OCaml (ocaml-multicore/ocaml-multicore#779).

[kit-ty-kate]

Thanks a lot!