From d966178f470a6c390634d4ec86584598505bb5fe Mon Sep 17 00:00:00 2001
From: Gary Verhaegen <gary.verhaegen@digitalasset.com>
Date: Mon, 14 Sep 2020 19:31:06 +0200
Subject: [PATCH] add indication of DAML_SDK_VERSION for daml version (#7385)

Fixes #7381.

```
$ alias daml=~/.daml/sdk/0.0.0/daml/daml
$ daml version
DAML SDK versions:
  0.0.0
  1.4.0
  1.5.0-snapshot.20200811.4959.0.bbc2fe56
  1.5.0-snapshot.20200818.5027.0.1b33d374
  1.5.0-snapshot.20200902.5118.0.2b3cf1b3  (default SDK version for new projects)
$ DAML_SDK_VERSION=invalid daml version
daml: Invalid value for environment variable DAML_SDK_VERSION.
  context: Determining SDK version and path.
  details: Invalid SDK version  "invalid": Failed reading: takeWhile1

$ DAML_SDK_VERSION=1.4.4 daml version
DAML SDK versions:
  0.0.0
  1.4.0
  1.4.4                                    (selected by env var DAML_SDK_VERSION, not installed)
  1.5.0-snapshot.20200811.4959.0.bbc2fe56
  1.5.0-snapshot.20200818.5027.0.1b33d374
  1.5.0-snapshot.20200902.5118.0.2b3cf1b3  (default SDK version for new projects)
$ DAML_SDK_VERSION=1.4.0 daml version
DAML SDK versions:
  0.0.0
  1.4.0                                    (selected by env var DAML_SDK_VERSION)
  1.5.0-snapshot.20200811.4959.0.bbc2fe56
  1.5.0-snapshot.20200818.5027.0.1b33d374
  1.5.0-snapshot.20200902.5118.0.2b3cf1b3  (default SDK version for new projects)
$ DAML_SDK_VERSION=1.5.0-snapshot.20200902.5118.0.2b3cf1b3 daml version
DAML SDK versions:
  0.0.0
  1.4.0
  1.5.0-snapshot.20200811.4959.0.bbc2fe56
  1.5.0-snapshot.20200818.5027.0.1b33d374
  1.5.0-snapshot.20200902.5118.0.2b3cf1b3  (selected by env var DAML_SDK_VERSION, default SDK version for new projects)
$
```

CHANGELOG_BEGIN
CHANGELOG_END
---
 daml-assistant/exe/DA/Daml/Assistant.hs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/daml-assistant/exe/DA/Daml/Assistant.hs b/daml-assistant/exe/DA/Daml/Assistant.hs
index b0d4859cc1..7181b1b5fe 100644
--- a/daml-assistant/exe/DA/Daml/Assistant.hs
+++ b/daml-assistant/exe/DA/Daml/Assistant.hs
@@ -11,13 +11,14 @@ import qualified DA.Service.Logger as L
 import qualified DA.Service.Logger.Impl.Pure as L
 import qualified DA.Service.Logger.Impl.GCP as L
 import DA.Daml.Project.Config
+import DA.Daml.Project.Consts (sdkVersionEnvVar)
 import DA.Daml.Assistant.Types
 import DA.Daml.Assistant.Env
 import DA.Daml.Assistant.Command
 import DA.Daml.Assistant.Version
 import DA.Daml.Assistant.Install
 import DA.Daml.Assistant.Util
-import System.Environment (getArgs)
+import System.Environment (getArgs, lookupEnv)
 import System.FilePath
 import System.Directory
 import System.Process.Typed
@@ -181,6 +182,7 @@ runCommand env@Env{..} = \case
         availableVersionsE <- tryAssistant $ refreshAvailableSdkVersions envDamlPath
         defaultVersionM <- tryAssistantM $ getDefaultSdkVersion envDamlPath
         projectVersionM <- mapM getSdkVersionFromProjectPath envProjectPath
+        envSelectedVersionM <- lookupEnv sdkVersionEnvVar
         snapshotVersionsE <- tryAssistant $
             if vSnapshots
                 then getAvailableSdkSnapshotVersions
@@ -212,7 +214,9 @@ runCommand env@Env{..} = \case
                     Right vs -> (`elem` vs)
 
             versionAttrs v = catMaybes
-                [ "project SDK version from daml.yaml"
+                [ ("selected by env var " <> pack sdkVersionEnvVar)
+                    <$ guard (Just (unpack $ versionToText v) == envSelectedVersionM)
+                , "project SDK version from daml.yaml"
                     <$ guard (Just v == projectVersionM && isJust envProjectPath)
                 , "default SDK version for new projects"
                     <$ guard (Just v == defaultVersionM && isNothing envProjectPath)