title: Rails 4 SQLite3::ReadOnlyException: attempt to write a readonly database
body: <p>I keep receiving the error <code>SQLite3::ReadOnlyException: attempt to write a readonly database: UPDATE "users" SET "current_sign_in_at" = ?, "sign_in_count" = ?, "updated_at" = ? WHERE "users"."id" = ?</code> when trying to sign into my Rails 4 app which uses the devise gem.</p>
  
  <p>I figured it has something to do with permissions on the dev db so checked out the permissions of the dir first, it has a <code>+</code> tacked onto the end which after some googling still couldn't figure out what it's doing.</p>
  
  <pre><code>-rw-r--r--   1 a36971  staff   2.1K 24 Jan 20:16 Gemfile
  -rw-r--r--   1 a36971  staff   5.7K 24 Jan 20:16 Gemfile.lock
  -rw-r--r--   1 a36971  staff    47B  7 Jan 22:31 README.md
  -rw-r--r--+  1 root    staff   249B  7 Jan 19:57 Rakefile
  drwxr-xr-x+  8 root    staff   272B  7 Jan 19:57 app/
  drwxr-xr-x+  7 root    staff   238B  7 Jan 19:57 bin/
  drwxr-xr-x+ 13 root    staff   442B 22 Jan 20:14 config/
  -rw-r--r--+  1 root    staff   153B  7 Jan 19:57 config.ru
  drwxr-xr-x+  8 root    staff   272B 26 Jan 10:28 db/
  drwxr-xr-x+  4 root    staff   136B  7 Jan 19:57 lib/
  drwxr-xr-x+  5 root    staff   170B  8 Jan 15:51 log/
  drwxr-xr-x+  7 root    staff   238B  7 Jan 19:57 public/
  drwxr-xr-x   7 a36971  staff   238B 17 Jan 22:38 spec/
  drwxr-xr-x+  9 root    staff   306B  7 Jan 19:57 test/
  drwxr-xr-x+  6 root    staff   204B  7 Jan 20:19 tmp/
  drwxr-xr-x+  3 root    staff   102B  7 Jan 19:57 vendor/
  </code></pre>
  
  <p>After <code>cd</code> ing into the db dir you can see there's nothing wrong with the permissions on the db itself:</p>
  
  <pre><code>-rw-r--r--  1 a36971  staff    44K 26 Jan 09:30 development.sqlite3
  drwxr-xr-x  5 a36971  staff   170B 22 Jan 20:14 migrate/
  -rw-r--r--  1 a36971  staff   2.2K 22 Jan 20:14 schema.rb
  -rw-r--r--  1 a36971  staff   1.2K 25 Jan 23:22 seeds.rb
  -rw-r--r--  1 a36971  staff    44K 26 Jan 09:23 test.sqlite3
  </code></pre>
  
  <p>So my questions are: </p>
  
  <p>a) why is it unable to write to the db when there doesn't appear to be anything wrong with the permissions themselves</p>
  
  <p>b) what does the <code>+</code> mean on mac os?</p>