title: Should diff return nothing after rsync?
body: <p>I just created a backup with </p>
  
  <pre><code>rsync -av --delete projects/ /Volumes/daten/projects/
  </code></pre>
  
  <p>Afterwards I ran </p>
  
  <pre><code>diff -r projects/ /Volumes/daten/projects/
  </code></pre>
  
  <p>just to check if everything's fine expecting no output from diff. However, diff found a lot of differences. Does that mean rsync did not correctly sync my data?</p>
  
  <p><strong>Update:</strong> When rerunning rsync it seems fine, there is nothing to do for rsync:</p>
  
  <pre><code>$ rsync -av --delete projects/ /Volumes/daten/projects/
  building file list ... done
  
  sent 470414 bytes  received 20 bytes  188173.60 bytes/sec
  total size is 295619054  speedup is 628.40
  </code></pre>
  
  <p>However, diff doesn't stop to generate output, as if there are lots of different files. Here is a small excerpt:</p>
  
  <pre><code>$ diff -r projects/ /Volumes/daten/projects/
  diff -r projects/CatClicker/app/build/intermediates/incremental/ir_dep/debug/package_dependencies/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_dep/debug/package_dependencies/dex-renamer-state.txt
  1c1
  &lt; #Sat Dec 08 16:17:41 CST 2018
  ---
  &gt; #Sun Nov 04 19:34:13 CET 2018
  diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_1/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_1/dex-renamer-state.txt
  1c1
  &lt; #Sat Dec 08 16:17:41 CST 2018
  ---
  &gt; #Sun Nov 04 19:34:14 CET 2018
  diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_2/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_2/dex-renamer-state.txt
  1c1
  &lt; #Sat Dec 08 16:17:41 CST 2018
  ---
  &gt; #Sun Nov 04 19:34:14 CET 2018
  diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_3/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_3/dex-renamer-state.txt
  1c1
  &lt; #Sat Dec 08 16:17:42 CST 2018
  ---
  &gt; #Sun Nov 04 19:34:14 CET 2018
  diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_4/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_4/dex-renamer-state.txt
  1c1
  &lt; #Sat Dec 08 16:17:42 CST 2018
  ---
  &gt; #Sun Nov 04 19:52:00 CET 2018
  diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_5/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_5/dex-renamer-state.txt
  1c1
  &lt; #Sat Dec 08 16:17:42 CST 2018
  ---
  &gt; #Sun Nov 04 19:34:14 CET 2018
  diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_6/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_6/dex-renamer-state.txt
  1c1
  &lt; #Sat Dec 08 16:17:42 CST 2018
  ---
  &gt; #Sun Nov 04 19:34:14 CET 2018
  diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_7/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_7/dex-renamer-state.txt
  1c1
  &lt; #Sat Dec 08 16:17:42 CST 2018
  ---
  &gt; #Sun Nov 04 19:34:14 CET 2018
  diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_8/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_8/dex-renamer-state.txt
  1c1
  &lt; #Sat Dec 08 16:17:42 CST 2018
  ---
  &gt; #Sun Nov 04 19:34:14 CET 2018
  diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_9/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_9/dex-renamer-state.txt
  1c1
  &lt; #Sat Dec 08 16:17:42 CST 2018
  ---
  &gt; #Sun Nov 04 19:34:14 CET 2018
  diff -r projects/CatClicker/app/build/intermediates/incremental/packageInstantRunResourcesDebug/tmp/debug/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/packageInstantRunResourcesDebug/tmp/debug/dex-renamer-state.txt
  1c1
  &lt; #Sat Dec 08 16:17:34 CST 2018
  ---
  &gt; #Sun Nov 04 19:33:52 CET 2018
  Binary files projects/CatClicker/app/build/intermediates/incremental-classes/debug/instant-run-bootstrap.jar and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-classes/debug/instant-run-bootstrap.jar differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/compat/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/compat/R$color.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/coreui/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/coreui/R$color.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/coreutils/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/coreutils/R$color.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/fragment/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/fragment/R$color.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/graphics/drawable/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/graphics/drawable/R$color.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/graphics/drawable/animated/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/graphics/drawable/animated/R$color.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/mediacompat/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/mediacompat/R$color.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/v4/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/v4/R$color.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/v7/appcompat/R$anim.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/v7/appcompat/R$anim.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/v7/appcompat/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/v7/appcompat/R$color.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$attr.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$attr.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$bool.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$bool.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$dimen.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$dimen.class differ
  Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$drawable.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$drawable.class differ
  </code></pre>