UNKOWN error thrown when compiling typescript using Gulp in VS2015

Question

I have installed Visual Studio 2015 (with no other previous versions) on a new laptop and have pulled down the source for our MVC web app. We have a gulp file with tasks to compile our less and typescript.

When running this task ...

cmd.exe /c gulp -b "C:\Code\Trunk\MyProj\MyProj.Web" --color --gulpfile "C:\Code\Trunk\MyProj\MyProj.Web\Gulpfile.js" typescript

... I get the following error:

[09:43:16] Using gulpfile C:\Code\Trunk\MyProj\MyProj.Web\Gulpfile.js
[09:43:16] Starting 'typescript'...
[09:43:34] Plumber found unhandled error:
 Error: UNKNOWN, open 'C:\Code\Trunk\MyProj\MyProj.Web\app\allergy\main.js'
Process terminated with code 0.

Here is the task in the gulp file (with other parts removed for brevity):

var gulp = require("gulp");
var plumber = require("gulp-plumber");
var sourcemaps = require("gulp-sourcemaps");
var typescript = require("gulp-typescript");
var merge = require("merge2");

var paths = {
    typescript: {
        globpatterns: {
            all: "./Scripts/**/*.ts",
            excludedefinitions: "!./Scripts/**/*.d.ts"
        }
    }
};

gulp.task("typescript", function () {
    var result = gulp.src([
            paths.typescript.globpatterns.all,
            paths.typescript.globpatterns.excludedefinitions
        ])
        .pipe(plumber())
        .pipe(sourcemaps.init())
        .pipe(typescript({
            removeComments: true,
            declarationFiles: false,
            noImplicitAny: false,
            noEmitOnError: true,
            module: "amd",
            target: "ES5"
        }));

    return merge([
        result.js.pipe(gulp.dest("./")),
        result.pipe(sourcemaps.write()).pipe(gulp.dest("./"))
    ]);
});

My colleague has the same set-up as me and gets no error.
Typescript is set to version 1.0 in the project file (<TypeScriptToolsVersion>1.0</TypeScriptToolsVersion>) and I can't change this just now. I wondered if the reason was beacuse I don't have this version installed on my machine but my colleague doesn't either. C:\Program Files (x86)\Microsoft SDKs\TypeScript only has a folder for 1.7
I noticed that the task completes successfully if I remove either of the 2 lines with in the merge block.
It's a different .js file in the error message each time

I searched the web to see what the UNKNOWN error even means but couldn't find anything obvious / helpful. Anyone know how to fix this error? Or how I go about finding out why it's being thrown?

EDIT 20-Jan-2016

So, I was getting this error consistently for about a week ... and now it has stopped happening. I haven't made any changes to my development environment either. I'd like to leave this question open since I'm curious as to why this happened.

UNKOWN error thrown when compiling typescript using Gulp in VS2015

0 Answers0