Bug/callback not on main thread

Example/Podfile

@@ -7,6 +7,21 @@ target 'KZFileWatchers_Example' do
   target 'KZFileWatchers_Tests' do
     inherit! :search_paths
 
+    # Nimble linking fails due to now-missing libswiftXCTest
+    # https://github.com/Quick/Nimble/issues/855#issuecomment-831810467
+    post_install do |installer|
+        installer.pods_project.targets.each do |target|
+            if target.name == "Nimble"
+                target.build_configurations.each do |config|
+                    xcconfig_path = config.base_configuration_reference.real_path
+                    xcconfig = File.read(xcconfig_path)
+                    new_xcconfig = xcconfig.sub('lswiftXCTest', 'lXCTestSwiftSupport')
+                    File.open(xcconfig_path, "w") { |file| file << new_xcconfig }
+                end
+            end
+        end
+    end
+
     pod 'Quick', '~> 2.1'
     pod 'Nimble', '~> 8.0'
     pod 'OHHTTPStubs/Swift', '~> 6.1.0'

Example/Podfile.lock

@@ -1,5 +1,5 @@
 PODS:
-  - KZFileWatchers (1.0.6)
+  - KZFileWatchers (1.1.0)
   - Nimble (8.0.4)
   - OHHTTPStubs/Core (6.1.0)
   - OHHTTPStubs/Default (6.1.0):
@@ -23,22 +23,21 @@ DEPENDENCIES:
   - Quick (~> 2.1)
 
 SPEC REPOS:
-  https://github.com/CocoaPods/Specs.git:
-    - OHHTTPStubs
   trunk:
     - Nimble
+    - OHHTTPStubs
     - Quick
 
 EXTERNAL SOURCES:
   KZFileWatchers:
     :path: "../"
 
 SPEC CHECKSUMS:
-  KZFileWatchers: 13c296495714ef41ddfd5c3fb0b2d0ee175fe42e
+  KZFileWatchers: e7f6236d145947f40ffbf863cee15ab0e8a8f053
   Nimble: 18d5360282923225d62b09d781f63abc1a0111fc
   OHHTTPStubs: 1e21c7d2c084b8153fc53d48400d8919d2d432d0
   Quick: 7fb19e13be07b5dfb3b90d4f9824c855a11af40e
 
-PODFILE CHECKSUM: 722bc3f808bc3fa80574e3ba352cd710a09b552d
+PODFILE CHECKSUM: 124813333fd3226dd446e45f73bede0e7dbd9c3e
 
-COCOAPODS: 1.8.0
+COCOAPODS: 1.10.1