OS X failure: Check failed: type_code_ == kTVMType (11 vs. 6) expected TVMType but get bytes

[ezyang]

After compiling and installing TVM on Mac OS X (with CUDA disabled, of course), when I attempt to use the Python API I get the following error:

(tvm) MacBook-Pro-97:python ezyang$ python
Python 3.6.2 | packaged by conda-forge | (default, Jul 23 2017, 23:01:38) 
[GCC 4.2.1 Compatible Apple LLVM 6.1.0 (clang-602.0.53)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import tvm
>>> tvm.var('a')
[12:19:27] dmlc-core/include/dmlc/logging.h:304: [12:19:27] include/tvm/./runtime/./packed_func.h:273: Check failed: type_code_ == kTVMType (11 vs. 6)  expected TVMType but get bytes

Stack trace returned 6 entries:
[bt] (0) 0   libtvm.so                           0x00000001103612e8 _ZN4dmlc15LogMessageFatalD2Ev + 40
[bt] (1) 1   libtvm.so                           0x0000000110365fe9 _ZNK3tvm7runtime11TVMArgValuecv10DLDataTypeEv + 393
[bt] (2) 2   libtvm.so                           0x00000001103687fa _ZNSt3__110__function6__funcIN3tvm2ir3$_0ENS_9allocatorIS4_EEFvNS2_7runtime7TVMArgsEPNS7_11TVMRetValueEEEclEOS8_OSA_ + 122
[bt] (3) 3   libtvm.so                           0x000000011060b62b TVMFuncCall + 75
[bt] (4) 4   _ctypes.cpython-36m-darwin.so       0x000000010f47f2b7 ffi_call_unix64 + 79
[bt] (5) 5   ???                                 0x00007fff50f154f0 0x0 + 140734551381232

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/ezyang/Dev/tvm/python/tvm/api.py", line 115, in var
    return _api_internal._Var(name, dtype)
  File "/Users/ezyang/Dev/tvm/python/tvm/_ffi/function.py", line 255, in my_api_func
    return flocal(*args)
  File "/Users/ezyang/Dev/tvm/python/tvm/_ffi/_ctypes/function.py", line 183, in __call__
    ctypes.byref(ret_val), ctypes.byref(ret_tcode)))
  File "/Users/ezyang/Dev/tvm/python/tvm/_ffi/base.py", line 62, in check_call
    raise TVMError(py_str(_LIB.TVMGetLastError()))
tvm._ffi.base.TVMError: [12:19:27] include/tvm/./runtime/./packed_func.h:273: Check failed: type_code_ == kTVMType (11 vs. 6)  expected TVMType but get bytes

Stack trace returned 6 entries:
[bt] (0) 0   libtvm.so                           0x00000001103612e8 _ZN4dmlc15LogMessageFatalD2Ev + 40
[bt] (1) 1   libtvm.so                           0x0000000110365fe9 _ZNK3tvm7runtime11TVMArgValuecv10DLDataTypeEv + 393
[bt] (2) 2   libtvm.so                           0x00000001103687fa _ZNSt3__110__function6__funcIN3tvm2ir3$_0ENS_9allocatorIS4_EEFvNS2_7runtime7TVMArgsEPNS7_11TVMRetValueEEEclEOS8_OSA_ + 122
[bt] (3) 3   libtvm.so                           0x000000011060b62b TVMFuncCall + 75
[bt] (4) 4   _ctypes.cpython-36m-darwin.so       0x000000010f47f2b7 ffi_call_unix64 + 79
[bt] (5) 5   ???                                 0x00007fff50f154f0 0x0 + 140734551381232

I'm willing to debug but posting here in case anyone has ideas.

[tqchen]

There are two types for std::string in TVM.

• kStr which is the type we need and can be casted safely to TVMType implicitly
• kBytes which represent the binary blob(cannot be casted to TVMType)

In python side, string_types will be translated to kStr, while bytearray(for both py2, py3) are translated to kBytes.

This error is caused by passing bytes into type field of var(which I don't know why)

[ezyang]

This turned out to be user error. I'll file a different bug explaining why.