it appears container must be privilged in either mode

cpsievert · cpsievert · commit 49c030fb3b81 · 2018-10-04T20:58:39.000-05:00
diff --git a/.travis.yml b/.travis.yml
@@ -28,7 +28,7 @@ before_install:
   
 # run visual tests on r-release
 before_script:
-  - if [[ "$TRAVIS_R_VERSION_STRING" == "release" ]]; then docker run -e VMODE="ci" -v $(pwd):/home/plotly cpsievert/plotly-orca; fi
+  - if [[ "$TRAVIS_R_VERSION_STRING" == "release" ]]; then docker run -e VMODE="ci" -v $(pwd):/home/plotly --privileged cpsievert/plotly-orca; fi
 
 # work around temporary travis + R 3.5 bug
 r_packages: devtools  
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -25,7 +25,7 @@ This will launch a shiny app for inspecting and validating any visual difference
 If, for some reason, you want to just run the visual tests to see if they'll pass, do:
 
 ```shell
-docker run -e VMODE="ci" -v $(pwd):/home/plotly cpsievert/plotly-orca
+docker run -e VMODE="ci" -v $(pwd):/home/plotly --privileged cpsievert/plotly-orca
 ```
 
 ## Code of Conduct
