factored cuda_setup.main out into smaller modules and functions

9 files changed, 385 insertions, 241 deletions

diff --git a/bitsandbytes/__init__.py b/bitsandbytes/__init__.py
index 76a5b48..7901f96 100644
--- a/bitsandbytes/__init__.py
+++ b/bitsandbytes/__init__.py
@@ -22,3 +22,5 @@ __pdoc__ = {
     "optim.optimizer.Optimizer8bit": False,
     "optim.optimizer.MockArgs": False,
 }
+
+PACKAGE_GITHUB_URL = "https://github.com/TimDettmers/bitsandbytes"
diff --git a/bitsandbytes/__main__.py b/bitsandbytes/__main__.py
index a91e942..7f3d24c 100644
--- a/bitsandbytes/__main__.py
+++ b/bitsandbytes/__main__.py
@@ -1,3 +1,96 @@
-from bitsandbytes.debug_cli import cli
+# from bitsandbytes.debug_cli import cli
 
-cli()
+# cli()
+import os
+import sys
+import torch
+
+
+HEADER_WIDTH = 60
+
+
+def print_header(
+    txt: str, width: int = HEADER_WIDTH, filler: str = "+"
+) -> None:
+    txt = f" {txt} " if txt else ""
+    print(txt.center(width, filler))
+
+
+def print_debug_info() -> None:
+    print(
+        "\nAbove we output some debug information. Please provide this info when "
+        f"creating an issue via {PACKAGE_GITHUB_URL}/issues/new/choose ...\n"
+    )
+
+
+print_header("")
+print_header("DEBUG INFORMATION")
+print_header("")
+print()
+
+
+from . import COMPILED_WITH_CUDA, PACKAGE_GITHUB_URL
+from .cuda_setup.main import get_compute_capabilities
+from .cuda_setup.env_vars import to_be_ignored
+from .utils import print_stderr
+
+
+print_header("POTENTIALLY LIBRARY-PATH-LIKE ENV VARS")
+for k, v in os.environ.items():
+    if "/" in v and not to_be_ignored(k, v):
+        print(f"'{k}': '{v}'")
+print_header("")
+
+print(
+    "\nWARNING: Please be sure to sanitize sensible info from any such env vars!\n"
+)
+
+print_header("OTHER")
+print(f"{COMPILED_WITH_CUDA = }")
+print(f"COMPUTE_CAPABILITIES_PER_GPU = {get_compute_capabilities()}")
+print_header("")
+print_header("DEBUG INFO END")
+print_header("")
+print(
+    """
+Running a quick check that:
+    + library is importable
+    + CUDA function is callable
+"""
+)
+
+try:
+    from bitsandbytes.optim import Adam
+
+    p = torch.nn.Parameter(torch.rand(10, 10).cuda())
+    a = torch.rand(10, 10).cuda()
+
+    p1 = p.data.sum().item()
+
+    adam = Adam([p])
+
+    out = a * p
+    loss = out.sum()
+    loss.backward()
+    adam.step()
+
+    p2 = p.data.sum().item()
+
+    assert p1 != p2
+    print("SUCCESS!")
+    print("Installation was successful!")
+    sys.exit(0)
+
+except ImportError:
+    print()
+    print_stderr(
+        f"WARNING: {__package__} is currently running as CPU-only!\n"
+        "Therefore, 8-bit optimizers and GPU quantization are unavailable.\n\n"
+        f"If you think that this is so erroneously,\nplease report an issue!"
+    )
+    print_debug_info()
+    sys.exit(0)
+except Exception as e:
+    print(e)
+    print_debug_info()
+    sys.exit(1)
diff --git a/bitsandbytes/cextension.py b/bitsandbytes/cextension.py
index f5b97fd..66c79d8 100644
--- a/bitsandbytes/cextension.py
+++ b/bitsandbytes/cextension.py
@@ -1,8 +1,8 @@
 import ctypes as ct
-import os
+from pathlib import Path
 from warnings import warn
 
-from bitsandbytes.cuda_setup.main import evaluate_cuda_setup
+from .cuda_setup.main import evaluate_cuda_setup
 
 
 class CUDALibrary_Singleton(object):
@@ -12,18 +12,17 @@ class CUDALibrary_Singleton(object):
         raise RuntimeError("Call get_instance() instead")
 
     def initialize(self):
-        self.context = {}
         binary_name = evaluate_cuda_setup()
-        if not os.path.exists(os.path.dirname(__file__) + f"/{binary_name}"):
+        package_dir = Path(__file__).parent
+        binary_path = package_dir / binary_name
+
+        if not binary_path.exists():
             print(f"TODO: compile library for specific version: {binary_name}")
-            print("defaulting to libbitsandbytes.so")
-            self.lib = ct.cdll.LoadLibrary(
-                os.path.dirname(__file__) + "/libbitsandbytes.so"
-            )
+            legacy_binary_name = "libbitsandbytes.so"
+            print(f"Defaulting to {legacy_binary_name}...")
+            self.lib = ct.cdll.LoadLibrary(package_dir / legacy_binary_name)
         else:
-            self.lib = ct.cdll.LoadLibrary(
-                os.path.dirname(__file__) + f"/{binary_name}"
-            )
+            self.lib = ct.cdll.LoadLibrary(package_dir / binary_name)
 
     @classmethod
     def get_instance(cls):
diff --git a/bitsandbytes/cuda_setup/env_vars.py b/bitsandbytes/cuda_setup/env_vars.py
new file mode 100644
index 0000000..536a7d8
--- /dev/null
+++ b/bitsandbytes/cuda_setup/env_vars.py
@@ -0,0 +1,51 @@
+import os
+from typing import Dict
+
+
+def to_be_ignored(env_var: str, value: str) -> bool:
+    ignorable = {
+        "PWD",  # PWD: this is how the shell keeps track of the current working dir
+        "OLDPWD",
+        "SSH_AUTH_SOCK",  # SSH stuff, therefore unrelated
+        "SSH_TTY",
+        "HOME",  # Linux shell default
+        "TMUX",  # Terminal Multiplexer
+        "XDG_DATA_DIRS",  # XDG: Desktop environment stuff
+        "XDG_RUNTIME_DIR",
+        "MAIL",  # something related to emails
+        "SHELL",  # binary for currently invoked shell
+        "DBUS_SESSION_BUS_ADDRESS",  # hardware related
+        "PATH",  # this is for finding binaries, not libraries
+        "LESSOPEN",  # related to the `less` command
+        "LESSCLOSE",
+        "_",  # current Python interpreter
+    }
+    return env_var in ignorable
+
+
+def might_contain_a_path(candidate: str) -> bool:
+    return "/" in candidate
+
+
+def is_active_conda_env(env_var: str) -> bool:
+    return "CONDA_PREFIX" == env_var
+
+
+def is_other_conda_env_var(env_var: str) -> bool:
+    return "CONDA" in env_var
+
+
+def is_relevant_candidate_env_var(env_var: str, value: str) -> bool:
+    return is_active_conda_env(env_var) or (
+        might_contain_a_path(value) and not
+        is_other_conda_env_var(env_var) and not
+        to_be_ignored(env_var, value)
+    )
+
+
+def get_potentially_lib_path_containing_env_vars() -> Dict[str, str]:
+    return {
+        env_var: value
+        for env_var, value in os.environ.items()
+        if is_relevant_candidate_env_var(env_var, value)
+    }
diff --git a/bitsandbytes/cuda_setup/main.py b/bitsandbytes/cuda_setup/main.py
index 6d70c92..e96ac70 100644
--- a/bitsandbytes/cuda_setup/main.py
+++ b/bitsandbytes/cuda_setup/main.py
@@ -8,8 +8,6 @@ extract factors the build is dependent on:
     - CuBLAS-LT: full-build 8-bit optimizer
     - no CuBLAS-LT: no 8-bit matrix multiplication (`nomatmul`)
 
-alle Binaries packagen
-
 evaluation:
     - if paths faulty, return meaningful error
     - else:
@@ -19,11 +17,10 @@ evaluation:
 """
 
 import ctypes
-import os
 from pathlib import Path
-from typing import Set, Union
 
-from ..utils import print_err, warn_of_missing_prerequisite, execute_and_return
+from ..utils import execute_and_return
+from .paths import determine_cuda_runtime_lib_path
 
 
 def check_cuda_result(cuda, result_val):
@@ -34,26 +31,23 @@ def check_cuda_result(cuda, result_val):
         raise Exception(f"CUDA exception! ERROR: {error_str}")
 
 
-# taken from https://gist.github.com/f0k/63a664160d016a491b2cbea15913d549
-def get_compute_capability():
-    # 1. find libcuda.so library (GPU driver) (/usr/lib)
-    #    init_device -> init variables -> call function by reference
-    # 2. call extern C function to determine CC 
-    #    (https://docs.nvidia.com/cuda/cuda-driver-api/group__CUDA__DEVICE__DEPRECATED.html)
-    # 3. Check for CUDA errors
-    #    https://stackoverflow.com/questions/14038589/what-is-the-canonical-way-to-check-for-errors-using-the-cuda-runtime-api
+def get_compute_capabilities():
+    """
+    1. find libcuda.so library (GPU driver) (/usr/lib)
+       init_device -> init variables -> call function by reference
+    2. call extern C function to determine CC
+       (https://docs.nvidia.com/cuda/cuda-driver-api/group__CUDA__DEVICE__DEPRECATED.html)
+    3. Check for CUDA errors
+       https://stackoverflow.com/questions/14038589/what-is-the-canonical-way-to-check-for-errors-using-the-cuda-runtime-api
+    # bits taken from https://gist.github.com/f0k/63a664160d016a491b2cbea15913d549
+    """
 
     # 1. find libcuda.so library (GPU driver) (/usr/lib)
-    libnames = ("libcuda.so",)
-    for libname in libnames:
-        try:
-            cuda = ctypes.CDLL(libname)
-        except OSError:
-            continue
-        else:
-            break
-    else:
-        raise OSError("could not load any of: " + " ".join(libnames))
+    try:
+        cuda = ctypes.CDLL("libcuda.so")
+    except OSError:
+        # TODO: shouldn't we error or at least warn here?
+        return None
 
     nGpus = ctypes.c_int()
     cc_major = ctypes.c_int()
@@ -70,104 +64,64 @@ def get_compute_capability():
         check_cuda_result(cuda, cuda.cuDeviceGet(ctypes.byref(device), i))
         ref_major = ctypes.byref(cc_major)
         ref_minor = ctypes.byref(cc_minor)
-        # 2. call extern C function to determine CC 
-        check_cuda_result(cuda, cuda.cuDeviceComputeCapability(ref_major, ref_minor, device))
-        ccs.append(f"{cc_major.value}.{cc_minor.value}")
-
-    # TODO: handle different compute capabilities; for now, take the max
-    ccs.sort()
-    max_cc = ccs[-1]
-    return max_cc
-
-
-CUDA_RUNTIME_LIB: str = "libcudart.so"
-
-
-def tokenize_paths(paths: str) -> Set[Path]:
-    return {Path(ld_path) for ld_path in paths.split(":") if ld_path}
-
-
-def resolve_env_variable(env_var):
-    '''Searches a given envirionmental library or path for the CUDA runtime library (libcudart.so)'''
-    paths: Set[Path] = tokenize_paths(env_var)
-
-    non_existent_directories: Set[Path] = {
-        path for path in paths if not path.exists()
-    }
-
-    if non_existent_directories:
-        print_err(
-            "WARNING: The following directories listed your path were found to "
-            f"be non-existent: {non_existent_directories}"
+        # 2. call extern C function to determine CC
+        check_cuda_result(
+            cuda, cuda.cuDeviceComputeCapability(ref_major, ref_minor, device)
         )
+        ccs.append(f"{cc_major.value}.{cc_minor.value}")
 
-    cuda_runtime_libs: Set[Path] = {
-        path / CUDA_RUNTIME_LIB
-        for path in paths
-        if (path / CUDA_RUNTIME_LIB).is_file()
-    } - non_existent_directories
+    return ccs.sort()
 
-    if len(cuda_runtime_libs) > 1:
-        err_msg = (
-            f"Found duplicate {CUDA_RUNTIME_LIB} files: {cuda_runtime_libs}.."
-        )
-        raise FileNotFoundError(err_msg)
-    elif len(cuda_runtime_libs) == 0: return None # this is not en error, since other envs can contain CUDA
-    else: return next(iter(cuda_runtime_libs)) # for now just return the first
-
-def get_cuda_runtime_lib_path() -> Union[Path, None]:
-    '''Searches conda installation and environmental paths for a cuda installations.'''
-
-    cuda_runtime_libs = []
-    # CONDA_PREFIX/lib is the default location for a default conda
-    # install of pytorch. This location takes priortiy over all
-    # other defined variables
-    if 'CONDA_PREFIX' in os.environ:
-        lib_conda_path = f'{os.environ["CONDA_PREFIX"]}/lib/'
-        print(lib_conda_path)
-        cuda_runtime_libs.append(resolve_env_variable(lib_conda_path))
-
-    if len(cuda_runtime_libs) == 1: return cuda_runtime_libs[0]
-
-    # if CONDA_PREFIX does not have the library, search the environment
-    # (in particualr LD_LIBRARY PATH)
-    for var in os.environ:
-         cuda_runtime_libs.append(resolve_env_variable(var))
-
-    if len(cuda_runtime_libs) < 1:
-        err_msg = (
-            f"Did not find {CUDA_RUNTIME_LIB} files: {cuda_runtime_libs}.."
-        )
-        raise FileNotFoundError(err_msg)
 
-    return cuda_runtime_libs.pop()
+# def get_compute_capability()-> Union[List[str, ...], None]: # FIXME: error
+def get_compute_capability():
+    """
+    Extracts the highest compute capbility from all available GPUs, as compute
+    capabilities are downwards compatible. If no GPUs are detected, it returns
+    None.
+    """
+    if ccs := get_compute_capabilities() is not None:
+        # TODO: handle different compute capabilities; for now, take the max
+        return ccs[-1]
+    return None
 
 
 def evaluate_cuda_setup():
-    cuda_path = get_cuda_runtime_lib_path()
-    print(f'CUDA SETUP: CUDA path found: {cuda_path}')
+    cuda_path = determine_cuda_runtime_lib_path()
+    print(f"CUDA SETUP: CUDA path found: {cuda_path}")
     cc = get_compute_capability()
     binary_name = "libbitsandbytes_cpu.so"
 
+    # FIXME: has_gpu is still unused
     if not (has_gpu := bool(cc)):
         print(
             "WARNING: No GPU detected! Check your CUDA paths. Processing to load CPU-only library..."
         )
         return binary_name
 
+    # 7.5 is the minimum CC vor cublaslt
     has_cublaslt = cc in ["7.5", "8.0", "8.6"]
 
     # TODO:
     # (1) CUDA missing cases (no CUDA installed by CUDA driver (nvidia-smi accessible)
     # (2) Multiple CUDA versions installed
 
+    # FIXME: cuda_home is still unused
     cuda_home = str(Path(cuda_path).parent.parent)
     # we use ls -l instead of nvcc to determine the cuda version
     # since most installations will have the libcudart.so installed, but not the compiler
     ls_output, err = execute_and_return(f"ls -l {cuda_path}")
-    major, minor, revision = ls_output.split(' ')[-1].replace('libcudart.so.', '').split('.')
+    major, minor, revision = (
+        ls_output.split(" ")[-1].replace("libcudart.so.", "").split(".")
+    )
     cuda_version_string = f"{major}{minor}"
 
-    binary_name = f'libbitsandbytes_cuda{cuda_version_string}{("" if has_cublaslt else "_nocublaslt")}.so'
+    def get_binary_name():
+        "if not has_cublaslt (CC < 7.5), then we have to choose  _nocublaslt.so"
+        bin_base_name = "libbitsandbytes_cuda"
+        if has_cublaslt:
+            return f"{bin_base_name}{cuda_version_string}.so"
+        else:
+            return f"{bin_base_name}_nocublaslt.so"
 
     return binary_name
diff --git a/bitsandbytes/cuda_setup/paths.py b/bitsandbytes/cuda_setup/paths.py
new file mode 100644
index 0000000..c4a7465
--- /dev/null
+++ b/bitsandbytes/cuda_setup/paths.py
@@ -0,0 +1,126 @@
+from pathlib import Path
+from typing import Set, Union
+from warnings import warn
+
+from ..utils import print_stderr
+from .env_vars import get_potentially_lib_path_containing_env_vars
+
+
+CUDA_RUNTIME_LIB: str = "libcudart.so"
+
+
+def purge_unwanted_semicolon(tentative_path: Path) -> Path:
+    """
+    Special function to handle the following exception:
+    __LMOD_REF_COUNT_PATH=/sw/cuda/11.6.2/bin:2;/mmfs1/home/dettmers/git/sched/bin:1;/mmfs1/home/dettmers/data/anaconda3/bin:1;/mmfs1/home/dettmers/data/anaconda3/condabin:1;/mmfs1/home/dettmers/.local/bin:1;/mmfs1/home/dettmers/bin:1;/usr/local/bin:1;/usr/bin:1;/usr/local/sbin:1;/usr/sbin:1;/mmfs1/home/dettmers/.fzf/bin:1;/mmfs1/home/dettmers/data/local/cuda-11.4/bin:1
+    """
+    # if ';' in str(tentative_path):
+    #     path_as_str, _ = str(tentative_path).split(';')
+    pass
+
+
+def extract_candidate_paths(paths_list_candidate: str) -> Set[Path]:
+    return {Path(ld_path) for ld_path in paths_list_candidate.split(":") if ld_path}
+
+
+def remove_non_existent_dirs(candidate_paths: Set[Path]) -> Set[Path]:
+    non_existent_directories: Set[Path] = {
+        path for path in candidate_paths if not path.exists()
+    }
+
+    if non_existent_directories:
+        print_stderr(
+            "WARNING: The following directories listed in your path were found to "
+            f"be non-existent: {non_existent_directories}"
+        )
+
+    return candidate_paths - non_existent_directories
+
+
+def get_cuda_runtime_lib_paths(candidate_paths: Set[Path]) -> Set[Path]:
+    return {
+        path / CUDA_RUNTIME_LIB
+        for path in candidate_paths
+        if (path / CUDA_RUNTIME_LIB).is_file()
+    }
+
+
+def resolve_paths_list(paths_list_candidate: str) -> Set[Path]:
+    """
+    Searches a given environmental var for the CUDA runtime library,
+    i.e. `libcudart.so`.
+    """
+    return remove_non_existent_dirs(extract_candidate_paths(paths_list_candidate))
+
+
+def find_cuda_lib_in(paths_list_candidate: str) -> Set[Path]:
+    return get_cuda_runtime_lib_paths(
+        resolve_paths_list(paths_list_candidate)
+    )
+
+
+def warn_in_case_of_duplicates(results_paths: Set[Path]) -> None:
+    if len(results_paths) > 1:
+        warning_msg = (
+            f"Found duplicate {CUDA_RUNTIME_LIB} files: {results_paths}.. "
+            "We'll flip a coin and try one of these, in order to fail forward.\n"
+            "Either way, this might cause trouble in the future:\n"
+            "If you get `CUDA error: invalid device function` errors, the above "
+            "might be the cause and the solution is to make sure only one "
+            f"{CUDA_RUNTIME_LIB} in the paths that we search based on your env."
+        )
+        warn(warning_msg)
+
+
+def determine_cuda_runtime_lib_path() -> Union[Path, None]:
+    """
+        Searches for a cuda installations, in the following order of priority:
+            1. active conda env
+            2. LD_LIBRARY_PATH
+            3. any other env vars, while ignoring those that
+                - are known to be unrelated (see `bnb.cuda_setup.env_vars.to_be_ignored`)
+                - don't contain the path separator `/`
+
+        If multiple libraries are found in part 3, we optimistically try one,
+        while giving a warning message.
+    """
+    candidate_env_vars = get_potentially_lib_path_containing_env_vars()
+
+    if "CONDA_PREFIX" in candidate_env_vars:
+        conda_libs_path = Path(candidate_env_vars["CONDA_PREFIX"]) / "lib"
+
+        conda_cuda_libs = find_cuda_lib_in(str(conda_libs_path))
+        warn_in_case_of_duplicates(conda_cuda_libs)
+
+        if conda_cuda_libs:
+            return next(iter(conda_cuda_libs))
+
+        warn(
+            f'{candidate_env_vars["CONDA_PREFIX"]} did not contain '
+            f'{CUDA_RUNTIME_LIB} as expected! Searching further paths...'
+        )
+
+    if "LD_LIBRARY_PATH" in candidate_env_vars:
+        lib_ld_cuda_libs = find_cuda_lib_in(candidate_env_vars["LD_LIBRARY_PATH"])
+
+        if lib_ld_cuda_libs:
+            return next(iter(lib_ld_cuda_libs))
+        warn_in_case_of_duplicates(lib_ld_cuda_libs)
+
+        warn(
+            f'{candidate_env_vars["LD_LIBRARY_PATH"]} did not contain '
+            f'{CUDA_RUNTIME_LIB} as expected! Searching further paths...'
+        )
+
+    remaining_candidate_env_vars = {
+        env_var: value for env_var, value in candidate_env_vars.items()
+        if env_var not in {"CONDA_PREFIX", "LD_LIBRARY_PATH"}
+    }
+
+    cuda_runtime_libs = set()
+    for env_var, value in remaining_candidate_env_vars:
+        cuda_runtime_libs.update(find_cuda_lib_in(value))
+
+    warn_in_case_of_duplicates(cuda_runtime_libs)
+
+    return next(iter(cuda_runtime_libs)) if cuda_runtime_libs else set()
diff --git a/bitsandbytes/utils.py b/bitsandbytes/utils.py
index e1d9460..4256a87 100644
--- a/bitsandbytes/utils.py
+++ b/bitsandbytes/utils.py
@@ -1,9 +1,9 @@
-import sys
 import shlex
 import subprocess
-
+import sys
 from typing import Tuple
 
+
 def execute_and_return(command_string: str) -> Tuple[str, str]:
     def _decode(subprocess_err_out_tuple):
         return tuple(
@@ -24,9 +24,9 @@ def execute_and_return(command_string: str) -> Tuple[str, str]:
     return std_out, std_err
 
 
-def print_err(s: str) -> None:
+def print_stderr(s: str) -> None:
     print(s, file=sys.stderr)
 
 
 def warn_of_missing_prerequisite(s: str) -> None:
-    print_err("WARNING, missing pre-requisite: " + s)
+    print_stderr("WARNING, missing pre-requisite: " + s)
diff --git a/quicktest.py b/quicktest.py
deleted file mode 100644
index 0fcda64..0000000
--- a/quicktest.py
+++ /dev/null
@@ -1,112 +0,0 @@
-from itertools import product
-
-import torch
-
-import bitsandbytes as bnb
-import bitsandbytes.functional as F
-
-
-def test_igemmlt(dim1, dim2, dim3, dim4, dims, ldb):
-    k = 25
-    for i in range(k):
-        if dims == 2:
-            A = torch.randint(-128, 127, size=(dim1, dim3), device="cuda").to(
-                torch.int8
-            )
-        elif dims == 3:
-            A = torch.randint(
-                -128, 127, size=(dim1, dim2, dim3), device="cuda"
-            ).to(torch.int8)
-        B = torch.randint(-128, 127, size=(dim4, dim3), device="cuda").to(
-            torch.int8
-        )
-        C1 = torch.matmul(A.float(), B.t().float())
-
-        A2, SA = F.transform(A, "col32")
-        B2, SB = F.transform(B, "colx")
-        if dims == 2:
-            C2, SC = F.transform(
-                torch.zeros(
-                    A.shape[0], B.shape[0], dtype=torch.int32, device="cuda"
-                ),
-                "col32",
-            )
-        else:
-            C2, SC = F.transform(
-                torch.zeros(
-                    A.shape[0],
-                    A.shape[1],
-                    B.shape[0],
-                    dtype=torch.int32,
-                    device="cuda",
-                ),
-                "col32",
-            )
-        F.igemmlt(A2, B2, C2, SA, SB, SC)
-        C3, S = F.transform(C2, "row", state=SC)
-        # torch.testing.assert_allclose(C1, C3.float())
-        # print(C1)
-        # print(C2)
-        # print(C3)
-        allclose = torch.allclose(C1, C3.float())
-        if allclose:
-            print(C1)
-            print(C2)
-            print(C3)
-
-        ## transposed
-        # A = torch.randint(-128, 127, size=(dim4, dim3), device='cuda').to(torch.int8)
-        # if dims == 2:
-        #    B = torch.randint(-128, 127, size=(dim1, dim3), device='cuda').to(torch.int8)
-        #    C1 = torch.matmul(A.float(), B.float().t())
-        # elif dims == 3:
-        #    B = torch.randint(-128, 127, size=(dim1, dim2, dim3), device='cuda').to(torch.int8)
-        #    C1 = torch.matmul(B.float(), A.t().float())
-        #    C1 = C1.permute([2, 0, 1])
-
-        # A2, SA = F.transform(A, 'col32')
-        # B2, SB = F.transform(B, 'colx')
-        # if dims == 2:
-        #    C2, SC = F.transform(torch.zeros(A.shape[0], B.shape[0], dtype=torch.int32, device='cuda'), 'col32')
-        # else:
-        #    C2 = torch.zeros(A.shape[0], B.shape[0], B.shape[1], dtype=torch.int32, device='cuda')
-        #    state = (C2.shape, 'row', A.shape[0])
-        #    C2, SC = F.transform(C2, 'col32', state=state)
-        # F.igemmlt(A2, B2, C2, SA, SB, SC)
-        # C3, S = F.transform(C2, 'row', state=SC, ld=[0])
-        # torch.testing.assert_allclose(C1, C3.float())
-
-        ## weight update
-        # if dims == 3:
-        #    A = torch.randint(-128, 127, size=(dim1, dim2, dim3), device='cuda').to(torch.int8)
-        #    B = torch.randint(-128, 127, size=(dim1, dim2, dim4), device='cuda').to(torch.int8)
-        #    C1 = torch.matmul(B.view(-1, B.shape[-1]).t().float(), A.view(-1, A.shape[-1]).float())
-
-        #    A2, SA = F.transform(A.view(-1, A.shape[-1]).t().contiguous(), 'colx')
-        #    B2, SB = F.transform(B.view(-1, B.shape[-1]).t().contiguous(), 'col32')
-        #    C2 = torch.zeros(B.shape[-1], A.shape[-1], dtype=torch.int32, device='cuda')
-        #    C2, SC = F.transform(C2, 'col32')
-        #    F.igemmlt(B2, A2, C2, SB, SA, SC)
-        #    C3, S = F.transform(C2, 'row', state=SC)
-        #    torch.testing.assert_allclose(C1, C3.float())
-
-
-dims = (2, 3)
-ldb = [0]
-
-n = 2
-dim1 = torch.randint(1, 256, size=(n,)).tolist()
-dim2 = torch.randint(32, 512, size=(n,)).tolist()
-dim3 = torch.randint(32, 1024, size=(n,)).tolist()
-dim4 = torch.randint(32, 1024, size=(n,)).tolist()
-values = list(product(dim1, dim2, dim3, dim4, dims, ldb))
-
-for ldb in range(32, 4096, 32):
-    # for ldb in [None]:
-    val = test_igemmlt(2, 2, 2, 2, 2, ldb)
-    if val:
-        print(val, ldb)
-    else:
-        print("nope", ldb)
-# for val in values:
-# test_igemmlt(*val)
diff --git a/tests/test_cuda_setup_evaluator.py b/tests/test_cuda_setup_evaluator.py
index 119e21a..3d34c29 100644
--- a/tests/test_cuda_setup_evaluator.py
+++ b/tests/test_cuda_setup_evaluator.py
@@ -7,10 +7,38 @@ from typing import List, NamedTuple
 from bitsandbytes.cuda_setup import (
     CUDA_RUNTIME_LIB,
     evaluate_cuda_setup,
-    get_cuda_runtime_lib_path,
-    tokenize_paths,
+    determine_cuda_runtime_lib_path,
+    extract_candidate_paths,
 )
 
+"""
+'LD_LIBRARY_PATH': ':/mnt/D/titus/local/cuda-11.1/lib64/'
+'CONDA_EXE': '/mnt/D/titus/miniconda/bin/conda'
+'LESSCLOSE': '/usr/bin/lesspipe %s %s'
+'OLDPWD': '/mnt/D/titus/src'
+'CONDA_PREFIX': '/mnt/D/titus/miniconda/envs/8-bit'
+'SSH_AUTH_SOCK': '/mnt/D/titus/.ssh/ssh-agent.tim-uw.sock'
+'CONDA_PREFIX_1': '/mnt/D/titus/miniconda'
+'PWD': '/mnt/D/titus/src/8-bit'
+'HOME': '/mnt/D/titus'
+'CONDA_PYTHON_EXE': '/mnt/D/titus/miniconda/bin/python'
+'CUDA_HOME': '/mnt/D/titus/local/cuda-11.1/'
+'TMUX': '/tmp/tmux-1007/default,59286,1'
+'XDG_DATA_DIRS': '/usr/local/share:/usr/share:/var/lib/snapd/desktop'
+'SSH_TTY': '/dev/pts/0'
+'MAIL': '/var/mail/titus'
+'SHELL': '/bin/bash'
+'DBUS_SESSION_BUS_ADDRESS': 'unix:path=/run/user/1007/bus'
+'XDG_RUNTIME_DIR': '/run/user/1007'
+'PATH': '/mnt/D/titus/miniconda/envs/8-bit/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/mnt/D/titus/local/cuda-11.1/bin'
+'LESSOPEN': '| /usr/bin/lesspipe %s'
+'_': '/mnt/D/titus/miniconda/envs/8-bit/bin/python'
+# any that include 'CONDA' that are not 'CONDA_PREFIX'
+
+# we search for
+'CUDA_HOME': '/mnt/D/titus/local/cuda-11.1/'
+"""
+
 
 class InputAndExpectedOutput(NamedTuple):
     input: str
@@ -47,20 +75,20 @@ HAPPY_PATH__LD_LIB_TEST_PATHS: List[InputAndExpectedOutput] = [
 
 @pytest.fixture(params=HAPPY_PATH__LD_LIB_TEST_PATHS)
 def happy_path_path_string(tmpdir, request):
-    for path in tokenize_paths(request.param):
+    for path in extract_candidate_paths(request.param):
         test_dir.mkdir()
         if CUDA_RUNTIME_LIB in path:
             (test_input / CUDA_RUNTIME_LIB).touch()
 
 
 @pytest.mark.parametrize("test_input, expected", HAPPY_PATH__LD_LIB_TEST_PATHS)
-def test_get_cuda_runtime_lib_path__happy_path(
+def test_determine_cuda_runtime_lib_path__happy_path(
     tmp_path, test_input: str, expected: str
 ):
-    for path in tokenize_paths(test_input):
+    for path in extract_candidate_paths(test_input):
         path.mkdir()
         (path / CUDA_RUNTIME_LIB).touch()
-    assert get_cuda_runtime_lib_path(test_input) == expected
+    assert determine_cuda_runtime_lib_path(test_input) == expected
 
 
 UNHAPPY_PATH__LD_LIB_TEST_PATHS = [
@@ -70,21 +98,21 @@ UNHAPPY_PATH__LD_LIB_TEST_PATHS = [
 
 
 @pytest.mark.parametrize("test_input", UNHAPPY_PATH__LD_LIB_TEST_PATHS)
-def test_get_cuda_runtime_lib_path__unhappy_path(tmp_path, test_input: str):
+def test_determine_cuda_runtime_lib_path__unhappy_path(tmp_path, test_input: str):
     test_input = tmp_path / test_input
     (test_input / CUDA_RUNTIME_LIB).touch()
     with pytest.raises(FileNotFoundError) as err_info:
-        get_cuda_runtime_lib_path(test_input)
+        determine_cuda_runtime_lib_path(test_input)
     assert all(match in err_info for match in {"duplicate", CUDA_RUNTIME_LIB})
 
 
-def test_get_cuda_runtime_lib_path__non_existent_dir(capsys, tmp_path):
+def test_determine_cuda_runtime_lib_path__non_existent_dir(capsys, tmp_path):
     existent_dir = tmp_path / "a/b"
     existent_dir.mkdir()
     non_existent_dir = tmp_path / "c/d"  # non-existent dir
     test_input = ":".join([str(existent_dir), str(non_existent_dir)])
 
-    get_cuda_runtime_lib_path(test_input)
+    determine_cuda_runtime_lib_path(test_input)
     std_err = capsys.readouterr().err
 
     assert all(match in std_err for match in {"WARNING", "non-existent"})
@@ -95,14 +123,17 @@ def test_full_system():
 
     # if CONDA_PREFIX exists, it has priority before all other env variables
     # but it does not contain the library directly, so we need to look at the a sub-folder
-    version = ''
-    if 'CONDA_PREFIX' in os.environ:
-        ls_output, err = bnb.utils.execute_and_return(f'ls -l {os.environ["CONDA_PREFIX"]}/lib/libcudart.so')
-        major, minor, revision = ls_output.split(' ')[-1].replace('libcudart.so.', '').split('.')
-        version = float(f'{major}.{minor}')
-
-
-    if version == '' and 'LD_LIBRARY_PATH':
+    version = ""
+    if "CONDA_PREFIX" in os.environ:
+        ls_output, err = bnb.utils.execute_and_return(
+            f'ls -l {os.environ["CONDA_PREFIX"]}/lib/libcudart.so'
+        )
+        major, minor, revision = (
+            ls_output.split(" ")[-1].replace("libcudart.so.", "").split(".")
+        )
+        version = float(f"{major}.{minor}")
+
+    if version == "" and "LD_LIBRARY_PATH":
         ld_path = os.environ["LD_LIBRARY_PATH"]
         paths = ld_path.split(":")
         version = ""