steven:~/bug$ valgrind ./bug
==13847== Memcheck, a memory error detector
==13847== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==13847== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info
==13847== Command: ./bug
==13847== 
==13847== Invalid read of size 4
==13847==    at 0x4FBA970: really_mark (in /home/kooda/coop/5.1.0-bug/lib/libchicken.so.11)
==13847==  Address 0xce5e4fac is not stack'd, malloc'd or (recently) free'd
==13847== 
==13847== Invalid read of size 4
==13847==    at 0x4FBAB70: really_remark (in /home/kooda/coop/5.1.0-bug/lib/libchicken.so.11)
==13847==  Address 0xce5e4fac is not stack'd, malloc'd or (recently) free'd
==13847== 
[panic] unrecoverable segmentation violation - execution terminated

bug.scm:3: srfi-4#u32vector
bug.scm:5: srfi-4#make-u32vector
bug.scm:9: chicken.locative#make-locative
bug.scm:10: chicken.locative#make-locative
bug.scm:9: chicken.locative#make-locative
bug.scm:10: chicken.locative#make-locative
bug.scm:9: chicken.locative#make-locative
bug.scm:10: chicken.locative#make-locative
bug.scm:9: chicken.locative#make-locative
bug.scm:10: chicken.locative#make-locative
bug.scm:9: chicken.locative#make-locative
bug.scm:10: chicken.locative#make-locative
bug.scm:15: chicken.gc#gc       <--
==13847== 
==13847== HEAP SUMMARY:
==13847==     in use at exit: 756,174 bytes in 2,728 blocks
==13847==   total heap usage: 2,729 allocs, 1 frees, 756,198 bytes allocated
==13847== 
==13847== LEAK SUMMARY:
==13847==    definitely lost: 4,096 bytes in 1 blocks
==13847==    indirectly lost: 0 bytes in 0 blocks
==13847==      possibly lost: 0 bytes in 0 blocks
==13847==    still reachable: 752,078 bytes in 2,727 blocks
==13847==         suppressed: 0 bytes in 0 blocks
==13847== Rerun with --leak-check=full to see details of leaked memory
==13847== 
==13847== For lists of detected and suppressed errors, rerun with: -s
==13847== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)