Feature/add 'prefix' argument to rez-pip

src/rez/cli/pip.py

@@ -24,6 +24,9 @@ def setup_parser(parser, completions=False):
         "-r", "--release", action="store_true",
         help="install as released package; if not set, package is installed "
         "locally only")
+    parser.add_argument(
+         "-p", "--install_path", type=str, metavar='PATH',
+         help="install package to a custom location")
     parser.add_argument(
         "PACKAGE",
         help="package to install or archive/url to install from")
@@ -55,7 +58,8 @@ def command(opts, parser, extra_arg_groups=None):
         opts.PACKAGE,
         pip_version=opts.pip_ver,
         python_version=opts.py_ver,
-        release=opts.release)
+        release=opts.release,
+        install_path=opts.install_path)
 
     # print summary
     #

src/rez/pip.py

@@ -192,7 +192,7 @@ def find_pip_from_context(python_version, pip_version=None):
 
 
 def pip_install_package(source_name, pip_version=None, python_version=None,
-                        mode=InstallMode.min_deps, release=False):
+                        mode=InstallMode.min_deps, release=False, install_path=None):
     """Install a pip-compatible python package as a rez package.
     Args:
         source_name (str): Name of package or archive/url containing the pip
@@ -223,8 +223,11 @@ def pip_install_package(source_name, pip_version=None, python_version=None,
 
     # TODO: should check if packages_path is writable before continuing with pip
     #
-    packages_path = (config.release_packages_path if release
-                     else config.local_packages_path)
+    if install_path is not None:
+        packages_path = install_path
+    else:
+        packages_path = (config.release_packages_path if release
+                         else config.local_packages_path)
 
     tmpdir = mkdtemp(suffix="-rez", prefix="pip-")
     stagingdir = os.path.join(tmpdir, "rez_staging")

wiki/pages/Pip.md

@@ -35,6 +35,8 @@ optional arguments:
   -s, --search          search for the package on PyPi
   -r, --release         install as released package; if not set, package is
                         installed locally only
+  -p PATH, --install_path PATH
+                        install package to a custom location
   -v, --verbose         verbose mode, repeat for more verbosity
 ```
 
@@ -107,8 +109,9 @@ remove your [user site](https://docs.python.org/3.7/library/site.html) from the
 You have two options when you want to convert a pip package to a rez package. You can
 install it, or release it. Install means that it will install in your
 [local_packages_path](Configuring-Rez#local_packages_path), while
-release means it will be installed in your
-[release_packages_path](Configuring-Rez#release_packages_path).
+release means it will be installed in your [release_packages_path](Configuring-Rez#release_packages_path).
+You can also specify a custom installation location using `--install_path` (or `-p`).
+
 
 You can (and we recommend) use the `--python-version` to choose for which python
 version you want to install a given package. This will make `rez-pip` to resolve