reimplement which

install.py

@@ -35,8 +35,8 @@
 # though rez is not yet built.
 #
 from rez.utils._version import _rez_version  # noqa: E402
+from rez.utils.which import which  # noqa: E402
 from rez.cli._entry_points import get_specifications  # noqa: E402
-from rez.backport.shutilwhich import which  # noqa: E402
 from rez.vendor.distlib.scripts import ScriptMaker  # noqa: E402
 
 # switch to builtin venv in python 3.7+

src/rez/resolved_context.py

@@ -31,7 +31,7 @@
 from rez.utils.filesystem import TempDirs, is_subdirectory, canonical_path
 from rez.utils.memcached import pool_memcached_connections
 from rez.utils.logging_ import print_error, print_warning
-from rez.backport.shutilwhich import which
+from rez.utils.which import which
 from rez.rex import RexExecutor, Python, OutputStyle
 from rez.rex_bindings import VersionBinding, VariantBinding, \
     VariantsBinding, RequirementsBinding, EphemeralsBinding, intersects

src/rez/shells.py

@@ -18,7 +18,7 @@
 """
 from rez.rex import RexExecutor, ActionInterpreter, OutputStyle
 from rez.util import shlex_join, is_non_string_iterable
-from rez.backport.shutilwhich import which
+from rez.utils.which import which
 from rez.utils.logging_ import print_warning
 from rez.utils.execution import Popen
 from rez.system import system

src/rez/status.py

@@ -27,7 +27,7 @@
 from rez.wrapper import Wrapper
 from rez.utils.colorize import warning, critical, Printer
 from rez.utils.formatting import print_colored_columns, PackageRequest
-from rez.backport.shutilwhich import which
+from rez.utils.which import which
 
 
 class Status(object):

src/rez/util.py

@@ -89,7 +89,8 @@ def escape_word(s):
 
 # returns path to first program in the list to be successfully found
 def which(*programs, **shutilwhich_kwargs):
-    from rez.backport.shutilwhich import which as which_
+    from rez.utils.which import which as which_
+
     for prog in programs:
         path = which_(prog, **shutilwhich_kwargs)
         if path:

src/rez/utils/which.py

@@ -0,0 +1,85 @@
+import os
+import sys
+
+
+_default_pathext = '.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC'
+
+
+def which(cmd, mode=os.F_OK | os.X_OK, path=None, env=None):
+    """A replacement for shutil.which.
+
+    Things we do that shutil.which does not:
+
+        * Support specifying `env`
+        * Take into account '%systemroot%' possible presence in `path` (windows)
+        * Take into account symlinks to executables (windows)
+    """
+    iswin = (sys.platform == "win32")
+    pathext = []
+    if env is None:
+        env = os.environ
+
+    # Check that a given file can be accessed with the correct mode.
+    # Additionally check that `file` is not a directory, as on Windows
+    # directories pass the os.access check.
+    #
+    def _access_check(fn, mode):
+        return (os.path.exists(fn) and os.access(fn, mode)
+                and not os.path.isdir(fn))
+
+    # If we're given a path with a directory part, look it up directly rather
+    # than referring to PATH directories. This includes checking relative to the
+    # current directory, e.g. ./script. Note that `path` is ignored in this case.
+    #
+    dirname, filename = os.path.split(cmd)
+    if dirname:
+        path = dirname
+        cmd = filename
+
+    if path is None:
+        path = env.get("PATH", os.defpath)
+    if not path:
+        return None
+    path = path.split(os.pathsep)
+
+    if iswin:
+        # The current directory takes precedence on Windows
+        if not dirname and os.curdir not in path:
+            path.insert(0, os.curdir)
+
+        # PATHEXT is necessary to check on Windows
+        pathext = env.get("PATHEXT", _default_pathext).split(os.pathsep)
+        pathext = [x.lower() for x in pathext]
+
+    # iterate over paths
+    seen = set()
+    for dir_ in path:
+        normdir = os.path.normcase(dir_)
+
+        # On windows the system paths might contain %systemroot%
+        normdir = os.path.expandvars(normdir)
+
+        if normdir in seen:
+            continue
+        seen.add(normdir)
+
+        # search for matching cmd
+        if iswin:
+            # Account for cmd possibly being a symlink. A symlink can be an
+            # executable on windows without an extension. If it is, see if its
+            # target's extension matches any of the expected path extensions.
+            #
+            realfile = os.path.realpath(os.path.join(normdir, cmd)).lower()
+            if any(realfile.endswith(x) for x in pathext):
+                files = [cmd]
+            else:
+                files = [(cmd + ext) for ext in pathext]
+        else:
+            files = [cmd]
+
+        for thefile in files:
+            name = os.path.join(normdir, thefile)
+            if _access_check(name, mode):
+                return name
+
+    return None

src/rez/vendor/README.md

@@ -236,18 +236,6 @@ Updated (July 2019) to coincide with packaging lib addition that depends on.
 Also now required to support py2/3 interoperability.
 </td></tr>
 
-<!-- ######################################################### -->
-<tr><td>
-whichcraft
-</td><td>
-0.6.1
-</td><td>
-BSD 3-Clause
-</td><td>
-https://github.com/cookiecutter/whichcraft<br>
-unmodified version added in commit f5b0ea0
-</td></tr>
-
 <!-- ######################################################### -->
 <tr><td>
 yaml lib (PyYAML)

src/rezplugins/build_system/cmake.py

@@ -26,7 +26,7 @@
 from rez.packages import get_developer_package
 from rez.utils.platform_ import platform_
 from rez.config import config
-from rez.backport.shutilwhich import which
+from rez.utils.which import which
 from rez.vendor.schema.schema import Or
 from rez.vendor.six import six
 from rez.shells import create_shell