From cf2572ce2f74c8a14d03886d7d7f7be901b9c3cf Mon Sep 17 00:00:00 2001
From: Jonathan Helmus <jjhelmus@gmail.com>
Date: Sat, 17 Jun 2017 11:27:38 -0500
Subject: [PATCH] Add --dry-run argument

The --dry-run argument can be used to list what distributions would be built
without actually performing the builds.
---
 conda_build_all/builder.py | 13 +++++++++++--
 conda_build_all/cli.py     |  5 ++++-
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/conda_build_all/builder.py b/conda_build_all/builder.py
index e4a0872..f677179 100644
--- a/conda_build_all/builder.py
+++ b/conda_build_all/builder.py
@@ -129,7 +129,8 @@ class Builder(object):
     def __init__(self, conda_recipes_directory,
                  inspection_channels, inspection_directories,
                  artefact_destinations,
-                 matrix_conditions, matrix_max_n_major_minor_versions=(2, 2)):
+                 matrix_conditions, matrix_max_n_major_minor_versions=(2, 2),
+                 dry_run=False):
         """
         Build a directory of conda recipes sequentially, if they don't already exist in the inspection locations.
 
@@ -149,6 +150,9 @@ def __init__(self, conda_recipes_directory,
             The number of major and minor versions to preserve for each resolved recipe. For instance,
             if a recipe can be built against np 1.7, 1.8 and 1.9, and the number of minor versions is 2,
             the build matrix will prune the 1.7 option.
+        dry_run : bool
+            True to stop before building recipes but after determining which
+            recipes to build.
 
         """
         self.conda_recipes_directory = conda_recipes_directory
@@ -157,6 +161,7 @@ def __init__(self, conda_recipes_directory,
         self.artefact_destinations = artefact_destinations
         self.matrix_conditions = matrix_conditions
         self.matrix_max_n_major_minor_versions = matrix_max_n_major_minor_versions
+        self.dry_run = dry_run
 
     def fetch_all_metas(self, config):
         """
@@ -242,7 +247,7 @@ def main(self):
             build_config = conda_build.config.config
 
         # If it is not already defined with environment variables, we set the CONDA_NPY
-        # to the latest possible value. Since we compute a build matrix anyway, this is 
+        # to the latest possible value. Since we compute a build matrix anyway, this is
         # useful to prevent conda-build bailing if the recipe depends on it (e.g.
         # ``numpy x.x``), and to ensure that recipes that don't care which version they want
         # at build/test time get a sensible version.
@@ -265,6 +270,10 @@ def main(self):
               '\n\t'.join(['{} (will be built: {})'.format(meta.dist(), dist_locn is None)
                            for meta, dist_locn in recipes_and_dist_locn])))
 
+        if self.dry_run:
+            print('Dry run: no distributions built')
+            return
+
         for meta, built_dist_location in recipes_and_dist_locn:
             was_built = built_dist_location is None
             if was_built:
diff --git a/conda_build_all/cli.py b/conda_build_all/cli.py
index 33fb93c..e8940c9 100644
--- a/conda_build_all/cli.py
+++ b/conda_build_all/cli.py
@@ -28,6 +28,9 @@ def main():
     parser.add_argument('--no-inspect-conda-bld-directory', default=False,
         action='store_true',
         help='Do not add the conda-build directory to the inspection list.')
+    parser.add_argument('--dry-run', default=False,
+        action='store_true',
+        help='Skip all builds, just list what distribution would be built.')
 
     parser.add_argument('--artefact-directory',
         help='A directory for any newly built distributions to be placed.')
@@ -86,7 +89,7 @@ def main():
                                         inspection_directories,
                                         artefact_destinations,
                                         args.matrix_conditions,
-                                        max_n_versions)
+                                        max_n_versions, args.dry_run)
     b.main()