Add missing documentation.

3 files changed, 17 insertions, 4 deletions

diff --git a/src/luarocks/build.lua b/src/luarocks/build.lua
index 71dcda94..dbe450ab 100644
--- a/src/luarocks/build.lua
+++ b/src/luarocks/build.lua
@@ -28,7 +28,9 @@ or the name of a rock to be fetched from a repository.
                     directory.
 
 --keep              Do not remove previously installed versions of the
-                    rock after building a new one.
+                    rock after building a new one. This behavior can
+                    be made permanent by setting keep_other_versions=true
+                    in the configuration file.
 ]]
 
 --- Install files to a given location.
diff --git a/src/luarocks/install.lua b/src/luarocks/install.lua
index 8ada2d50..e1b44203 100644
--- a/src/luarocks/install.lua
+++ b/src/luarocks/install.lua
@@ -20,6 +20,11 @@ help_arguments = "{<rock>|<name> [<version>]}"
 help = [[
 Argument may be the name of a rock to be fetched from a repository
 or a filename of a locally available rock.
+
+--keep              Do not remove previously installed versions of the
+                    rock after installing a new one. This behavior can
+                    be made permanent by setting keep_other_versions=true
+                    in the configuration file.
 ]]
 
 --- Install a binary rock.
diff --git a/src/luarocks/make.lua b/src/luarocks/make.lua
index 474662ac..eef49d0c 100644
--- a/src/luarocks/make.lua
+++ b/src/luarocks/make.lua
@@ -27,9 +27,15 @@ This command is useful as a tool for debugging rockspecs.
 To install rocks, you'll normally want to use the "install" and
 "build" commands. See the help on those for details.
 
-If --pack-binary-rock is passed, the rock is not installed;
-instead, a .rock file with the contents of compilation is produced
-in the current directory.
+--pack-binary-rock  Do not install rock. Instead, produce a .rock file
+                    with the contents of compilation in the current
+                    directory.
+
+--keep              Do not remove previously installed versions of the
+                    rock after installing a new one. This behavior can
+                    be made permanent by setting keep_other_versions=true
+                    in the configuration file.
+
 ]]
 
 --- Driver function for "make" command.