tct-1.15 won't make under i386 OpenBSD 3.5

Errors while making The Coroner's Toolkit v1.15 on i386 OpenBSD 3.5:
Can anyone help?

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chmod 700 .
cd src/aux; make "CC=gcc" MAKELEVEL=
cd src/misc; make "CC=gcc" MAKELEVEL=
cd src/fstools; make "CC=gcc" MAKELEVEL=
gcc -DOPENBSD3 -I../aux -O -g  -c ffs.c
ffs.c:39: field `dinode' has incomplete type
ffs.c: In function `ffs_dinode_lookup':
ffs.c:112: sizeof applied to an incomplete type
ffs.c:114: sizeof applied to an incomplete type
ffs.c: In function `ffs_copy_inode':
ffs.c:132: dereferencing pointer to incomplete type
ffs.c:133: dereferencing pointer to incomplete type
ffs.c:134: dereferencing pointer to incomplete type
ffs.c:135: dereferencing pointer to incomplete type
ffs.c:136: dereferencing pointer to incomplete type
ffs.c:137: dereferencing pointer to incomplete type
ffs.c:138: dereferencing pointer to incomplete type
ffs.c:139: dereferencing pointer to incomplete type
ffs.c:143: dereferencing pointer to incomplete type
ffs.c:145: dereferencing pointer to incomplete type
ffs.c: In function `ffs_inode_walk':
ffs.c:212: dereferencing pointer to incomplete type
ffs.c:219: dereferencing pointer to incomplete type
*** Error code 1

Stop in /tmp/tct-1.15/src/fstools.
*** Error code 1

Stop in /tmp/tct-1.15/src/fstools (line 17 of Makefile).
*** Error code 1

Stop in /tmp/tct-1.15 (line 14 of Makefile).