SQL Server: Failed to monitor external signals This program has encountered a fatal error and cannot continue running.
The following diagnostic information is available:

       Reason: 0x00000007
      Message: Failed to monitor external signals
      Process: 26596 - sqlservr
       Thread: 26600 (application thread 0x1000)
  Instance Id: 4065d66f-ef73-4bb1-bfe3-5a4ef091cdf0
     Crash Id: 71fa707f-be4b-4b39-9269-ec697e7b5baf
  Build stamp: 9a4c738f0e0d015cbf851ead55d593dc0c806bb1b05452f58289c247307d420d
*********** PAL PANIC CORE DUMP GENERATION FAILED **********
Unable to locate handle-crash.sh. Error 2.
*********** PANIC CORE DUMP GENERATION FAILED **********
Attempt to launch handle-crash.sh failed with error 0x00000002
Failed to connect to bus: No such file or directory
Attempting to start the Microsoft SQL Server service failed.


If I manually run, /opt/mssql/bin/sqlservr I get

Capturing core dump and information...
cat: /proc/27493/maps: No such file or directory
cat: /proc/sys/vm/max_map_count: No such file or directory
/opt/mssql/bin/crash-support-functions.sh: line 399: (100*0)/: syntax error: operand expected (error token is "/")
This is because you need make the hosts /proc accessable in the chroot, in order to do that you can use a --bind mount,

sudo mount --bind /proc /opt/mschroot/proc


Where /opt/mschroot is the location of your chroot.