using PyCall assertion error on ARM (julia master, crouton)

Probably a stupid questions, but what is the purpose of all the assertions? and Is there an easy way to compile /run julia, pycall, etc disabling assertions? (or is that a "bad idea"). **thanks!** -- perrin

``` julia
WARNING: deprecated syntax "call(::Type{PyAny}, ...)".
Use "(::Type{PyAny})(...)" instead.
WARNING: Base.writemime is deprecated.
likely near /home/perrin/.julia/v0.5/PyCall/src/PyCall.jl:604
WARNING: Base.writemime is deprecated.
likely near /home/perrin/.julia/v0.5/PyCall/src/PyCall.jl:604
WARNING: Base.writemime is deprecated.
likely near /home/perrin/.julia/v0.5/PyCall/src/PyCall.jl:604
WARNING: Base.writemime is deprecated.
likely near /home/perrin/.julia/v0.5/PyCall/src/PyCall.jl:604
WARNING: Base.writemime is deprecated.
likely near /home/perrin/.julia/v0.5/PyCall/src/PyCall.jl:604
WARNING: bytestring(s::AbstractString...) is deprecated, use string(s...) instead.
while loading /home/perrin/.julia/v0.5/PyCall/src/PyCall.jl, in expression starting on line 625
julia: /home/psmsd/julia_builds/julia_gitrocks/src/ccall.cpp:162: llvm::Value* llvm_type_rewrite(llvm::Value*, llvm::Type*, llvm::Type*, bool, bool, bool, jl_codectx_t*): Assertion `from_type->isPointerTy() == target_type->isPointerTy()' failed.

signal (6): Aborted
while loading /home/perrin/.julia/v0.5/PyCall/src/PyCall.jl, in expression starting on line 670
Allocations: 2732815 (Pool: 2731387; Big: 1428); GC: 10
ERROR: Failed to precompile PyCall to /home/perrin/.julia/lib/v0.5/PyCall.ji
```

**system info**

``` julia
(trusty)perrin@localhost:~/bin$ julia5
_
_ _ _(_)_ | A fresh approach to technical computing
(_) | (_) (_) | Documentation: http://docs.julialang.org
_ _ _| |_ __ _ | Type "?help" for help.
| | | | | | |/ _` | |
| | |_| | | | (_| | | Version 0.5.0-dev+4489 (2016-06-03 16:42 UTC)
_/ |\__'_|_|_|\__'_| | Commit fc22418 (0 days old master)
|__/ | arm-linux-gnueabihf

julia> versioninfo(true)
Julia Version 0.5.0-dev+4489
Commit fc22418 (2016-06-03 16:42 UTC)
Platform Info:
System: Linux (arm-linux-gnueabihf)
CPU: ARMv7 Processor rev 3 (v7l)
WORD_SIZE: 32
Ubuntu 14.04.4 LTS
uname: Linux 3.8.11 #1 SMP Thu May 12 00:22:47 PDT 2016 armv7l armv7l
Memory: 3.4568443298339844 GB (356.796875 MB free)
Uptime: 11337.0 sec
Load Avg: 1.236328125 1.01953125 0.9521484375
ARMv7 Processor rev 3 (v7l):
speed user nice sys idle irq
#1 2000 MHz 472447 s 123 s 82656 s 529776 s 19 s
#2 2000 MHz 476965 s 111 s 71431 s 559844 s 3 s
#3 2000 MHz 491658 s 108 s 70487 s 547001 s 2 s
#4 2000 MHz 458781 s 106 s 70051 s 581954 s 1 s

BLAS: libopenblas (NO_AFFINITY ARMV7)
LAPACK: libopenblas
LIBM: libm
LLVM: libLLVM-3.7.1 (ORCJIT, cortex-a15)
Environment:
TERM = xterm
PATH = /home/perrin/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games:/home/perrin/bin/
HOME = /home/perrin

Package Directory: /home/perrin/.julia/v0.5
1 required packages:
- PyPlot 2.1.1
13 additional packages:
- BinDeps 0.3.21
- ColorTypes 0.2.2
- Colors 0.6.4
- Compat 0.7.20
- Conda 0.2.0
- FixedPointNumbers 0.1.3
- JSON 0.5.1
- LaTeXStrings 0.1.6
- MacroTools 0.3.0
- PyCall 1.6.1
- Reexport 0.0.3
- SHA 0.1.2
- URIParser 0.1.3
```

Reproduce the PyCall precompilation failure on the reported ARMv7 environment, starting with PyCall/src/PyCall.jl around lines 604, 625, and 670. Inspect Julia's ccall.cpp at line 162 and determine why the pointer-type assertion fails; done means the failure is understood and PyCall precompiles successfully on the affected setup.

Written by the indexing model from the issue text.