Add an explanation of the format of the packages file format

1 files changed, 15 insertions, 0 deletions

diff --git a/packages b/packages
index 49f936b3af..547e4bffe9 100644
--- a/packages
+++ b/packages
@@ -1,6 +1,21 @@
 # Note that when adding libraries to this file, you also need to add
 # the library to the SUBDIRS variable in libraries/Makefile so that they
 # actually get built
+#
+# The format of the lines in this file is:
+#   localpath    (optional) tag    remotepath    VCS
+# where
+#   * localpath is where to put the repository in a checked out tree,
+#   * remotepath is where the repository is in the central repository,
+#   * VCS is what version control system the repo uses,
+#   * the tag, is present, determines when "darcs-all get" will get the
+#     repo. If there is no tag then it will always get it, but if there
+#     is a tag then a corresponding flag must be given to darcs-all, e.g.
+#     if you want to get the packages with an "extralibs" or "testsuite"
+#     tag then you need to use "darcs-all --extra --testsuite get".
+#     Support for new tags must be manually added to the darcs-all script.
+#
+# Lines that start with a '#' are comments.
 .                                       ghc                             git
 utils/hsc2hs                            hsc2hs                          darcs
 utils/haddock                           haddock2                        darcs