diff --git a/spec/atom-environment-spec.coffee b/spec/atom-environment-spec.coffee
index d967fb97b..d1eabf2c8 100644
--- a/spec/atom-environment-spec.coffee
+++ b/spec/atom-environment-spec.coffee
@@ -126,6 +126,7 @@ describe "AtomEnvironment", ->
 
     beforeEach ->
       errors = []
+      spyOn(atom, 'isReleasedVersion').andReturn(true)
       atom.onDidFailAssertion (error) -> errors.push(error)
 
     describe "if the condition is false", ->
@@ -147,6 +148,11 @@ describe "AtomEnvironment", ->
           atom.assert(false, "a == b", {foo: 'bar'})
           expect(errors[0].metadata).toEqual {foo: 'bar'}
 
+      describe "when Atom has been built from source", ->
+        it "throws an error", ->
+          atom.isReleasedVersion.andReturn(false)
+          expect(-> atom.assert(false, 'testing')).toThrow('Assertion failed: testing')
+
     describe "if the condition is true", ->
       it "does nothing", ->
         result = atom.assert(true, "a == b")
diff --git a/spec/dom-element-pool-spec.js b/spec/dom-element-pool-spec.js
index 9de932e27..91120ee48 100644
--- a/spec/dom-element-pool-spec.js
+++ b/spec/dom-element-pool-spec.js
@@ -3,7 +3,10 @@ const DOMElementPool = require ('../src/dom-element-pool')
 describe('DOMElementPool', function () {
   let domElementPool
 
-  beforeEach(() => { domElementPool = new DOMElementPool() })
+  beforeEach(() => {
+    domElementPool = new DOMElementPool()
+    spyOn(atom, 'isReleasedVersion').andReturn(true)
+  })
 
   it('builds DOM nodes, recycling them when they are freed', function () {
     let elements
diff --git a/spec/text-editor-spec.coffee b/spec/text-editor-spec.coffee
index 911270d16..81c69f63f 100644
--- a/spec/text-editor-spec.coffee
+++ b/spec/text-editor-spec.coffee
@@ -28,7 +28,13 @@ describe "TextEditor", ->
       editor.foldBufferRow(4)
       expect(editor.isFoldedAtBufferRow(4)).toBeTruthy()
 
-      editor2 = TextEditor.deserialize(editor.serialize(), atom)
+      editor2 = TextEditor.deserialize(editor.serialize(), {
+        assert: atom.assert,
+        textEditors: atom.textEditors,
+        project: {
+          bufferForIdSync: (id) -> TextBuffer.deserialize(editor.buffer.serialize())
+        }
+      })
 
       expect(editor2.id).toBe editor.id
       expect(editor2.getBuffer().getPath()).toBe editor.getBuffer().getPath()
diff --git a/spec/workspace-spec.coffee b/spec/workspace-spec.coffee
index 153cc5dc3..8e4da1185 100644
--- a/spec/workspace-spec.coffee
+++ b/spec/workspace-spec.coffee
@@ -7,6 +7,7 @@ platform = require './spec-helper-platform'
 _ = require 'underscore-plus'
 fstream = require 'fstream'
 fs = require 'fs-plus'
+AtomEnvironment = require '../src/atom-environment'
 
 describe "Workspace", ->
   [workspace, setDocumentEdited] = []
@@ -865,24 +866,35 @@ describe "Workspace", ->
         i = /test/; #FIXME
       """
 
-      state = atom.workspace.serialize()
-      expect(state.packagesWithActiveGrammars).toEqual ['language-coffee-script', 'language-javascript', 'language-todo']
-
-      jsPackage = atom.packages.getLoadedPackage('language-javascript')
-      coffeePackage = atom.packages.getLoadedPackage('language-coffee-script')
-      spyOn(jsPackage, 'loadGrammarsSync')
-      spyOn(coffeePackage, 'loadGrammarsSync')
-
-      workspace2 = new Workspace({
-        config: atom.config, project: atom.project, packageManager: atom.packages,
-        notificationManager: atom.notifications, deserializerManager: atom.deserializers,
-        viewRegistry: atom.views, grammarRegistry: atom.grammars,
-        applicationDelegate: atom.applicationDelegate, assert: atom.assert.bind(atom),
-        textEditorRegistry: atom.textEditors
+      atom2 = new AtomEnvironment({
+        applicationDelegate: atom.applicationDelegate,
+        window: document.createElement('div'),
+        document: Object.assign(
+          document.createElement('div'),
+          {
+            body: document.createElement('div'),
+            head: document.createElement('div'),
+          }
+        )
       })
-      workspace2.deserialize(state, atom.deserializers)
-      expect(jsPackage.loadGrammarsSync.callCount).toBe 1
-      expect(coffeePackage.loadGrammarsSync.callCount).toBe 1
+
+      atom2.packages.loadPackage('language-javascript')
+      atom2.packages.loadPackage('language-coffee-script')
+      atom2.packages.loadPackage('language-todo')
+      atom2.project.deserialize(atom.project.serialize())
+      atom2.workspace.deserialize(atom.workspace.serialize(), atom2.deserializers)
+
+      expect(atom2.grammars.getGrammars().map((grammar) -> grammar.name).sort()).toEqual([
+        'CoffeeScript',
+        'CoffeeScript (Literate)',
+        'JavaScript',
+        'Null Grammar',
+        'Regular Expression Replacement (JavaScript)',
+        'Regular Expressions (JavaScript)',
+        'TODO'
+      ])
+
+      atom2.destroy()
 
   describe "document.title", ->
     describe "when there is no item open", ->
@@ -971,18 +983,26 @@ describe "Workspace", ->
 
       it "updates the title to contain the project's path", ->
         document.title = null
-        workspace2 = new Workspace({
-          config: atom.config, project: atom.project, packageManager: atom.packages,
-          notificationManager: atom.notifications, deserializerManager: atom.deserializers,
-          viewRegistry: atom.views, grammarRegistry: atom.grammars,
-          applicationDelegate: atom.applicationDelegate, assert: atom.assert.bind(atom),
-          textEditorRegistry: atom.textEditors
+
+        atom2 = new AtomEnvironment({
+          applicationDelegate: atom.applicationDelegate,
+          window: document.createElement('div'),
+          document: Object.assign(
+            document.createElement('div'),
+            {
+              body: document.createElement('div'),
+              head: document.createElement('div'),
+            }
+          )
         })
-        workspace2.deserialize(atom.workspace.serialize(), atom.deserializers)
-        item = workspace2.getActivePaneItem()
+
+        atom2.project.deserialize(atom.project.serialize())
+        atom2.workspace.deserialize(atom.workspace.serialize(), atom2.deserializers)
+        item = atom2.workspace.getActivePaneItem()
         pathEscaped = fs.tildify(escapeStringRegex(atom.project.getPaths()[0]))
         expect(document.title).toMatch ///^#{item.getLongTitle()}\ \u2014\ #{pathEscaped}///
-        workspace2.destroy()
+
+        atom2.destroy()
 
   describe "document edited status", ->
     [item1, item2] = []
diff --git a/src/atom-environment.coffee b/src/atom-environment.coffee
index 3133b5af8..dc4318bec 100644
--- a/src/atom-environment.coffee
+++ b/src/atom-environment.coffee
@@ -840,6 +840,8 @@ class AtomEnvironment extends Model
         error.metadata = callbackOrMetadata
 
     @emitter.emit 'did-fail-assertion', error
+    unless @isReleasedVersion()
+      throw error
 
     false
 
diff --git a/src/text-editor.coffee b/src/text-editor.coffee
index 1f24fa252..8095632fd 100644
--- a/src/text-editor.coffee
+++ b/src/text-editor.coffee
@@ -387,7 +387,7 @@ class TextEditor extends Model
       softWrapHangingIndentLength: @displayLayer.softWrapHangingIndent
 
       @id, @softTabs, @softWrapped, @softWrapAtPreferredLineLength,
-      @preferredLineLength, @mini, @editorWidthInChars,  @width, @largeFileMode,
+      @preferredLineLength, @mini, @editorWidthInChars, @width, @largeFileMode,
       @registered, @invisibles, @showInvisibles, @showIndentGuide, @autoHeight, @autoWidth
     }