Update sassc gem and disable concurrency for precompile assets

Concurrency are raising failure during the precompile.
There is an issue on sprocket related to this issue
rails/sprockets#581 and
sass/sassc-ruby#138.

Author: David Kang

dist/obs-bundled-gems.spec

@@ -100,6 +100,7 @@ mkdir -p vendor/cache
 cp %{_sourcedir}/vendor/cache/*.gem vendor/cache
 export GEM_HOME=~/.gems
 bundle config build.nokogiri --use-system-libraries
+bundle config build.sassc --disable-march-tune-native
 
 %install
 bundle --local --path %{buildroot}%_libdir/obs-api/

src/api/Gemfile.lock

@@ -157,7 +157,7 @@ GEM
       tty-screen (~> 0.6.5)
       tty-tree (~> 0.3.0)
     feature (1.4.0)
-    ffi (1.11.1)
+    ffi (1.12.2)
     flot-rails (0.0.7)
       jquery-rails
     font-awesome-sass (5.8.1)
@@ -387,9 +387,8 @@ GEM
       crass (~> 1.0.2)
       nokogiri (>= 1.8.0)
       nokogumbo (~> 2.0)
-    sassc (2.0.1)
+    sassc (2.2.1)
       ffi (~> 1.9)
-      rake
     sassc-rails (2.1.2)
       railties (>= 4.0.0)
       sassc (>= 2.0)
@@ -439,7 +438,7 @@ GEM
       riddle (~> 2.3)
     thor (0.20.3)
     thread_safe (0.3.6)
-    tilt (2.0.9)
+    tilt (2.0.10)
     timecop (0.9.1)
     tins (1.20.3)
     tty-color (0.5.0)

src/api/config/initializers/assets.rb

@@ -9,3 +9,8 @@
 # Precompile additional assets.
 # application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
 Rails.application.config.assets.precompile += ['webui2/webui2.css', 'webui2/application.js', 'webui/obs_factory/application.css', 'webui2/cm2/*.js']
+
+# FIXME: Precompile are not thread safe
+Rails.application.config.assets.configure do |env|
+  env.export_concurrent = false
+end