Intel TBB is required, no threading layer could be loaded, however TBB is already installed

Using Numba 0.50.1, and Python 3.8.2, here is the code causing the bug:

from numba import config, njit, threading_layer
import numpy as np

# set the threading layer before any parallel target compilation
config.THREADING_LAYER = 'tbb'

@njit(parallel=True)
def foo(a, b):
	return a + b
x = np.arange(10.)
y = x.copy()

foo(x, y)
# demonstrate the threading layer chosen
print("Threading layer chosen: %s" % threading_layer())

Which gives me the error

Traceback (most recent call last):
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/errors.py", line 745, in new_error_context
    yield
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/lowering.py", line 273, in lower_block
    self.lower_inst(inst)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/lowering.py", line 486, in lower_inst
    func(self, inst)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/parfors/parfor_lowering.py", line 271, in _lower_parfor_parallel
    call_parallel_gufunc(
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/parfors/parfor_lowering.py", line 1398, in call_parallel_gufunc
    _launch_threads()
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/np/ufunc/parallel.py", line 486, in _launch_threads
    raise_with_hint(requirements)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/np/ufunc/parallel.py", line 431, in raise_with_hint
    raise ValueError(errmsg % hint)
ValueError: No threading layer could be loaded.
HINT:
Intel TBB is required, try:
$ conda/pip install tbb

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "test.py", line 17, in <module>
    foo(x, y)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/dispatcher.py", line 434, in _compile_for_args
    raise e
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/dispatcher.py", line 367, in _compile_for_args
    return self.compile(tuple(argtypes))
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/compiler_lock.py", line 32, in _acquire_compile_lock
    return func(*args, **kwargs)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/dispatcher.py", line 808, in compile
    cres = self._compiler.compile(args, return_type)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/dispatcher.py", line 78, in compile
    status, retval = self._compile_cached(args, return_type)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/dispatcher.py", line 92, in _compile_cached
    retval = self._compile_core(args, return_type)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/dispatcher.py", line 105, in _compile_core
    cres = compiler.compile_extra(self.targetdescr.typing_context,
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/compiler.py", line 603, in compile_extra
    return pipeline.compile_extra(func)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/compiler.py", line 339, in compile_extra
    return self._compile_bytecode()
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/compiler.py", line 401, in _compile_bytecode
    return self._compile_core()
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/compiler.py", line 381, in _compile_core
    raise e
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/compiler.py", line 372, in _compile_core
    pm.run(self.state)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/compiler_machinery.py", line 341, in run
    raise patched_exception
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/compiler_machinery.py", line 332, in run
    self._runPass(idx, pass_inst, state)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/compiler_lock.py", line 32, in _acquire_compile_lock
    return func(*args, **kwargs)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/compiler_machinery.py", line 291, in _runPass
    mutated |= check(pss.run_pass, internal_state)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/compiler_machinery.py", line 264, in check
    mangled = func(compiler_state)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/typed_passes.py", line 442, in run_pass
    NativeLowering().run_pass(state)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/typed_passes.py", line 370, in run_pass
    lower.lower()
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/lowering.py", line 179, in lower
    self.lower_normal_function(self.fndesc)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/lowering.py", line 233, in lower_normal_function
    entry_block_tail = self.lower_function_body()
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/lowering.py", line 259, in lower_function_body
    self.lower_block(block)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/lowering.py", line 273, in lower_block
    self.lower_inst(inst)
  File "/usr/lib/python3.8/contextlib.py", line 131, in __exit__
    self.gen.throw(type, value, traceback)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/errors.py", line 752, in new_error_context
    reraise(type(newerr), newerr, tb)
  File "/home/ilknull/.local/lib/python3.8/site-packages/numba/core/utils.py", line 81, in reraise
    raise value
numba.core.errors.LoweringError: Failed in nopython mode pipeline (step: nopython mode backend)
No threading layer could be loaded.
HINT:
Intel TBB is required, try:
$ conda/pip install tbb

File "test.py", line 10:
def foo(a, b):
	return a + b
 ^

During: lowering "id=0[LoopNest(index_variable = parfor_index.8, range = (0, a_size0.1, 1))]{1: <ir.Block at test.py (10)>}Var(parfor_index.8, test.py:10)" at test.py (10)

However, pip3 install tbb produces:

Requirement already satisfied: tbb in /home/ilknull/.local/lib/python3.8/site-packages (2020.0.133)

Any ways I could fix this issue? I’m not sure what is happening, I also used pip3 install numba to install Numba. Much appreciated

[JeppeDruedahl]

I have a similar problem. I have installed Anaconda3-2020.07-Windows-x86_64 (Python 3.8.3) on two computers. TBB is installed and running numba -s it is recognized. But I still get the error when setting the threading layer to ‘tbb’.

[stuartarchibald]

@HugoStrand Could you perhaps open a new issue about this please? The code as-is is to handle common problems in practice, patches to add improvements for dealing with diagnosing new problems are welcomed. This is possibly related https://github.com/numba/numba/issues/6108.