variable symbol changed from 'struct S1 v1' to 'struct { int a1; } v1'
  type changed from 'struct S1' to 'struct { int a1; }'

variable symbol changed from 'struct { int a2; } v2' to 'struct S2 v2'
  type changed from 'struct { int a2; }' to 'struct S2'

exit code 4