https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70601
--- Comment #6 from janus at gcc dot gnu.org ---
The backtrace on current trunk is:
call concrete % run()
internal compiler error: in fold_convert_loc, at fold-const.c:2239
0xb9ecfc fold_convert_loc(unsigned int, tree_node*, tree_node*)
/home/jweil/gcc/gcc7/trunk/gcc/fold-const.c:2238
0x8ca836 gfc_call_free(tree_node*)
/home/jweil/gcc/gcc7/trunk/gcc/fortran/trans.c:915
0x9233be gfc_conv_procedure_call(gfc_se*, gfc_symbol*, gfc_actual_arglist*,
gfc_expr*, vec<tree_node*, va_gc, vl_embed>*)
/home/jweil/gcc/gcc7/trunk/gcc/fortran/trans-expr.c:6095
0x975f28 gfc_trans_call(gfc_code*, bool, tree_node*, tree_node*, bool)
/home/jweil/gcc/gcc7/trunk/gcc/fortran/trans-stmt.c:407
0x8cd69f trans_code
/home/jweil/gcc/gcc7/trunk/gcc/fortran/trans.c:1780
0x8cdac7 gfc_trans_code(gfc_code*)
/home/jweil/gcc/gcc7/trunk/gcc/fortran/trans.c:2013
0x90ad56 gfc_generate_function_code(gfc_namespace*)
/home/jweil/gcc/gcc7/trunk/gcc/fortran/trans-decl.c:6261
0x8cdb0b gfc_generate_code(gfc_namespace*)
/home/jweil/gcc/gcc7/trunk/gcc/fortran/trans.c:2030
0x85cdf3 translate_all_program_units
/home/jweil/gcc/gcc7/trunk/gcc/fortran/parse.c:6038
0x85d468 gfc_parse_file()
/home/jweil/gcc/gcc7/trunk/gcc/fortran/parse.c:6238
0x8b64b3 gfc_be_parse_file
/home/jweil/gcc/gcc7/trunk/gcc/fortran/f95-lang.c:202
