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Setting "umask" might gradually break your macOS

Setting "umask" might gradually break your macOS

I had a hard time as I misconfigured “umask” setting on macOS.
So, I want to leave a note.

It was happened about 1 month after I setup “umask” on my Mac.
I didn’t understand what is happening as I already forgot about that.

1st error

I saw the 1st error when I updated on AppStore.

Library not loaded: @rpath/libffmpeg.dylib

It says, I felt, one of the required libs:

  • was deleted; or
  • was not included when bundle the app;

Nothing tell me about misconfiguration of “umask”

I found an GigHub ISSUE on Signal Desktop.

As both of Slack and Signal Desktop are using Electron,
I suspect the Electron framework might be the cause.

I Googled, but I couldn’t find any related information about that.

I, still, could use if I install it from web without AppStore. So, I leave the error at that time.

Real cause of this error

More time passed, and, more apps suffered this error.
And not only apps using Electron.

I also found:

  • some processes are not responding; and
  • cannot open “Security & Privacy” pane on;
  • /Application directory freeze;

Why, why, why??

Hints from’s log

So, I checked, and I found a lot of Permission denied errors.
I fixed those errors by fixing permission of files.

And also found logs like following

fault	00:00:00.000000+0000	sysextd	bad ownership/permissions on sysextd staging area

And I remember that “I set up umask before!!”


Execute the following command & restart, and fix broken permission using chmod.

sudo launchctl config system umask 022

Or, delete UMASK section from plist


We should be super careful when change umask on macOS, as described here.