Add DUNE_PROFILE environment variable

Signed-off-by: Rudi Grinberg <[email protected]>

Author: rgrinberg

CHANGES.md

@@ -127,6 +127,9 @@ unreleased
   preprocessing actions
   (#1812, fixes #1811, @diml)
 
+- Add `DUNE_PROFILE` environment variable to easily set the profile. (#1806,
+  @rgrinberg)
+
 1.6.2 (05/12/2018)
 ------------------
 

bin/common.ml

@@ -259,9 +259,12 @@ let term =
           `Error
             (true, "--dev is no longer accepted as it is now the default.")
       and profile =
+        let doc =
+          "Build profile. dev if unspecified or release if -p is set." in
         Arg.(value
              & opt (some string) None
              & info ["profile"] ~docs
+                 ~env:(Arg.env_var ~doc "DUNE_PROFILE")
                  ~doc:
                    (sprintf
                       {|Select the build profile, for instance $(b,dev) or