Forgot the init, added sourcemaps.init also ran yarn to add dependencies... (Yes they may have been there already)

Author: john-Graham

gulpfile.js

@@ -55,11 +55,13 @@ gulp.task('images', function() {
 // Development CSS creation.
 // Checks for errors and concats. Minifies.
 gulp.task('scss', function() {
-	return gulp.src( './'+src+'scss/**/*.scss')
+  return gulp.src( './'+src+'scss/**/*.scss')
+    .pipe(sourcemaps.init())
     .pipe(sass({outputStyle: 'compressed'}).on('error', sass.logError))
-    .pipe(sourcemaps.write())
+    .pipe(sourcemaps.write('.'))
     .pipe(rename({suffix: '.min'}))
     .pipe(autoprefixer({browsers: ['last 2 versions', 'ie >= 9', '> 1%']}))
+    .pipe(sourcemaps.write('.'))
 		.pipe(gulp.dest( './'+dist+'/css/'))
 		.pipe(notify({message: 'Styles compiled successfully!', title : 'sass', sound: false}));
 });
@@ -68,10 +70,11 @@ gulp.task('scss', function() {
 // Checks for errors and concats. Minifies. All Bootstrap CSS
 gulp.task('bscss', function() {
   return gulp.src('./'+src+assets+'bootstrap/scss/**/*.scss')
+    .pipe(sourcemaps.init())
     .pipe(sass({outputStyle: 'compressed'}).on('error', sass.logError))
-    .pipe(sourcemaps.write())
     .pipe(rename({suffix: '.min'}))
     .pipe(autoprefixer({browsers: ['last 2 versions', 'ie >= 9', '> 1%']}))
+    .pipe(sourcemaps.write('.'))
 		.pipe(gulp.dest( './'+dist+'css/'))
 		.pipe(notify({message: 'Styles compiled successfully!', title : 'bootstrap', sound: false}));
 })

package.json

@@ -22,7 +22,7 @@
     "gulp-replace": "^0.6.1",
     "gulp-sass": "^3.1.0",
     "gulp-sequence": "^1.0.0",
-    "gulp-sourcemaps": "^2.6.1",
+    "gulp-sourcemaps": "^2.6.4",
     "gulp-uglify": "^3.0.0",
     "gulp-zip": "^4.1.0",
     "jshint": "^2.9.5"

yarn.lock

@@ -1746,9 +1746,9 @@ gulp-sourcemaps@1.6.0:
     through2 "^2.0.0"
     vinyl "^1.0.0"
 
-gulp-sourcemaps@^2.6.1:
-  version "2.6.3"
-  resolved "https://registry.yarnpkg.com/gulp-sourcemaps/-/gulp-sourcemaps-2.6.3.tgz#11b033f759f909e0a5f15b7bdf47ac29cc54efa4"
+gulp-sourcemaps@^2.6.4:
+  version "2.6.4"
+  resolved "https://registry.yarnpkg.com/gulp-sourcemaps/-/gulp-sourcemaps-2.6.4.tgz#cbb2008450b1bcce6cd23bf98337be751bf6e30a"
   dependencies:
     "@gulp-sourcemaps/identity-map" "1.X"
     "@gulp-sourcemaps/map-sources" "1.X"
@@ -1758,7 +1758,7 @@ gulp-sourcemaps@^2.6.1:
     debug-fabulous "1.X"
     detect-newline "2.X"
     graceful-fs "4.X"
-    source-map "0.X"
+    source-map "~0.6.0"
     strip-bom-string "1.X"
     through2 "2.X"
 
@@ -3920,10 +3920,6 @@ source-map-url@~0.3.0:
   version "0.3.0"
   resolved "https://registry.yarnpkg.com/source-map-url/-/source-map-url-0.3.0.tgz#7ecaf13b57bcd09da8a40c5d269db33799d4aaf9"
 
-source-map@0.X, source-map@^0.6.1, source-map@~0.6.1:
-  version "0.6.1"
-  resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.6.1.tgz#74722af32e9614e9c287a8d0bbde48b5e2f1a263"
-
 source-map@^0.1.38:
   version "0.1.43"
   resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.1.43.tgz#c24bc146ca517c1471f5dacbe2571b2b7f9e3346"
@@ -3940,6 +3936,10 @@ source-map@^0.5.1, source-map@^0.5.3, source-map@^0.5.6:
   version "0.5.7"
   resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.5.7.tgz#8a039d2d1021d22d1ea14c80d8ea468ba2ef3fcc"
 
+source-map@^0.6.1, source-map@~0.6.0, source-map@~0.6.1:
+  version "0.6.1"
+  resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.6.1.tgz#74722af32e9614e9c287a8d0bbde48b5e2f1a263"
+
 sparkles@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/sparkles/-/sparkles-1.0.0.tgz#1acbbfb592436d10bbe8f785b7cc6f82815012c3"