Merge pull request #508 from bentayloruk/fix-fsiargs

Provide env var access to --fsiargs build script args so works on FAKE 3

help/commandline.md

@@ -56,6 +56,8 @@ Important:  If you use this option, you must include your build script path as o
 
 `--fsiargs --debug+ buildscript.fsx someArg1 anotherArg2`
 
+The entire argument string *following* the build script path is set as the value of an environment variable named `fsiargs-buildscriptargs`.  This means you can access this specific set of arguments from within your build script.
+
 ### `--boot [-b] <string>`
 
 Boostrapp your FAKE script.  A bootstrapping `build.fsx` script executes twice (in two stages), allowing you to download dependencies with NuGet and do other preparatory work in the first stage, and have these dependencies available in the second stage.

src/app/FakeLib/FSIHelper.fs

@@ -96,10 +96,13 @@ let runBuildScriptWithFsiArgsAt workingDirectory printDetails (FsiArgs(fsiOption
     for (k,v) in args do
       Environment.SetEnvironmentVariable(k, v, EnvironmentVariableTarget.Process)
 
+    // Create an env var that only contains the build script args part from the --fsiargs (or "").
+    Environment.SetEnvironmentVariable("fsiargs-buildscriptargs", String.Join(" ", scriptArgs))
+
     let fsiConfig = FsiEvaluationSession.GetDefaultConfiguration()
 
     let commonOptions = 
-        [ "fsi.exe"; "--noninteractive" ] @ fsiOptions @ scriptArgs
+        [ "fsi.exe"; "--noninteractive" ] @ fsiOptions
         |> List.toArray
 
     let sbOut = new Text.StringBuilder()