Improve dependency handling

It now won't report unsatisfiable dependencies between two nodes in the
dependency graph that are already installed.  E.g. previously, if one
used the --nodeps flag to install package "foo" that had a failed
dependency on Zeek, then installing unrelated package "bar" without
--nodeps would emit an error about "foo" dependencies being
unsatisfiable even though that has no relation to the current operation.

CHANGES

@@ -1,4 +1,15 @@
 
+2.0.4-1 | 2019-09-18 16:09:19 -0700
+
+  * Improve dependency handling (Jon Siwek, Corelight)
+
+    It now won't report unsatisfiable dependencies between two nodes in the
+    dependency graph that are already installed.  E.g. previously, if one
+    used the --nodeps flag to install package "foo" that had a failed
+    dependency on Zeek, then installing unrelated package "bar" without
+    --nodeps would emit an error about "foo" dependencies being
+    unsatisfiable even though that has no relation to the current operation.
+
 2.0.4 | 2019-08-28 15:50:13 -0700
 
   * Release 2.0.4.

VERSION

@@ -1 +1 @@
-2.0.4
+2.0.4-1

doc/man/zkg.1

@@ -1,6 +1,6 @@
 .\" Man page generated from reStructuredText.
 .
-.TH "ZKG" "1" "Aug 28, 2019" "2.0.4" "Zeek Package Manager"
+.TH "ZKG" "1" "Sep 18, 2019" "2.0.4-1" "Zeek Package Manager"
 .SH NAME
 zkg \- Zeek Package Manager
 .

zeekpkg/__init__.py

@@ -9,7 +9,7 @@
 
 import logging
 
-__version__ = "2.0.4"
+__version__ = "2.0.4-1"
 __all__ = ['manager', 'package', 'source']
 
 LOG = logging.getLogger(__name__)

zeekpkg/manager.py

@@ -1531,8 +1531,16 @@ def __str__(self):
                 # Check that installed version doesn't conflict with dependers.
                 track_method, required_version = node.installed_version
 
-                if track_method == TRACKING_METHOD_BRANCH:
-                    for depender_name, version_spec in node.dependers.items():
+                for depender_name, version_spec in node.dependers.items():
+                    if ( depender_name in graph and
+                         graph[depender_name].installed_version ):
+                        # Both nodes already installed, so assume compatible.
+                        # They're maybe not actually if the user installed via
+                        # --nodeps, but if that's their desired state, it's
+                        # better not to complain about it now.
+                        continue
+
+                    if track_method == TRACKING_METHOD_BRANCH:
                         if version_spec == '*':
                             continue
 
@@ -1547,8 +1555,7 @@ def __str__(self):
                             ' but "{}" requires {}', node.name,
                             required_version, depender_name, version_spec),
                             new_pkgs)
-                elif track_method == TRACKING_METHOD_COMMIT:
-                    for depender_name, version_spec in node.dependers.items():
+                    elif track_method == TRACKING_METHOD_COMMIT:
                         if version_spec == '*':
                             continue
 
@@ -1561,11 +1568,10 @@ def __str__(self):
                             ' but "{}" requires {}', node.name,
                             required_version, depender_name, version_spec),
                             new_pkgs)
-                else:
-                    normal_version = _normalize_version_tag(required_version)
-                    req_semver = semver.Version.coerce(normal_version)
+                    else:
+                        normal_version = _normalize_version_tag(required_version)
+                        req_semver = semver.Version.coerce(normal_version)
 
-                    for depender_name, version_spec in node.dependers.items():
                         if version_spec.startswith('branch='):
                             version_spec = version_spec[len('branch='):]
                             return (str.format(