From: Geoffrey Thomas Date: Wed, 3 Dec 2014 11:18:11 -0600 Subject: Prevent pip from removing system packages. Adjust is_local() to consider OS-owned paths non-local. Fix the error message for is_local() in the non-virtualenv case. Author: Geoffrey Thomas Bug-Debian: http://bugs.debian.org/771794 Origin: https://github.com/geofft/pip.git Forwarded: not-needed Reviewed-By: Donald Stufft Reviewed-By: Scott Kitterman Last-Update: 2014-12-04 Patch-Name: hands-off-system-packages.patch --- src/pip/_internal/utils/misc.py | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) diff --git a/src/pip/_internal/utils/misc.py b/src/pip/_internal/utils/misc.py index 4fb64d2..459312f 100644 --- a/src/pip/_internal/utils/misc.py +++ b/src/pip/_internal/utils/misc.py @@ -365,25 +365,44 @@ def renames(old, new): def is_local(path): # type: (str) -> bool """ - Return True if path is within sys.prefix, if we're running in a virtualenv. + Return True if this is a path pip is allowed to modify. - If we're not in a virtualenv, all paths are considered "local." + If we're in a virtualenv, sys.prefix points to the virtualenv's + prefix; only sys.prefix is considered local. + + If we're not in a virtualenv, in general we can modify anything. + However, if the OS vendor has configured distutils to install + somewhere other than sys.prefix (which could be a subdirectory of + sys.prefix, e.g. /usr/local), we consider sys.prefix itself nonlocal + and the domain of the OS vendor. (In other words, everything _other + than_ sys.prefix is considered local.) Caution: this function assumes the head of path has been normalized with normalize_path. """ - if not running_under_virtualenv(): - return True - return path.startswith(normalize_path(sys.prefix)) + + path = normalize_path(path) + # Hard-coded becouse PyPy uses a different sys.prefix on Debian + prefix = '/usr' + + if running_under_virtualenv(): + return path.startswith(normalize_path(sys.prefix)) + else: + from pip._internal.locations import distutils_scheme + if path.startswith(prefix): + for local_path in distutils_scheme("").values(): + if path.startswith(normalize_path(local_path)): + return True + return False + else: + return True def dist_is_local(dist): # type: (Distribution) -> bool """ - Return True if given Distribution object is installed locally - (i.e. within current virtualenv). - - Always True if we're not in a virtualenv. + Return True if given Distribution object is installed somewhere pip + is allowed to modify. """ return is_local(dist_location(dist))