https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70231
Bug ID: 70231 Summary: Runtime error: Different CHARACTER lengths in array constructor with allocatable array and -O0 Product: gcc Version: 5.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran Assignee: unassigned at gcc dot gnu.org Reporter: vladimir.fuka at gmail dot com Target Milestone: --- integer, parameter :: char_len = 32 character(char_len), allocatable :: ch_array(:) character(char_len) :: ch allocate(ch_array(0)) ch = "a" ch_array = [ch_array, ch] print *,ch_array(1) end compiled with gfortran -fcheck=all char_array.f90 causes runtime error At line 7 of file char_array.f90 Fortran runtime error: Different CHARACTER lengths (32709/32) in array constructor Works with -O1 and higher.