bin/cp/utils.c:517:14: error: member reference base type 'void' is not a structure or union (RESCUE)

A couple of weeks for now it is impossible to compile nanoBSD (based on
12-STABLE, most recent r365925), compiled on a host running recent
CURRENT (FreeBSD 13.0-CURRENT #0 r365487: Fri Sep 18 16:31:04 CEST 2020
amd64). Since the introduction of LLVM 10 to 12-STABLE and LLVM 11 to
CURRENT, the (cross) compilation of nanoBSD fails on the building host
with the error shown below. Although option "WITHOUT_RESCU" is set when
either building or building/installing the sources, the shown error
popps up.

The curious thing is, that I also build 12-STABLE jails on the same
CURRENT system the "tradiotional way" (means: building the 12-STABLE
and then installing the jail via ezjail-admin without interaction of
any foreign/network sources except the source repository. No error of
the shown kind ever occurs.

Can someon please explain this problem? It looks like a bug in a make
file.

Regards,

Oliver

[...]
cc -target x86_64-unknown-freebsd12.2
--sysroot=/pool/nanobsd/amd64/ALERICH_12-STABLE_amd64/pool/sources/12-STABLE/src/amd64.amd64/tmp
-B/pool/nanobsd/amd64/ALERICH_12-STABLE_amd64/pool/sources/12-STABLE/src/amd64.amd64/tmp/usr/bin
-pg  -O2 -pipe -O3 -pipe -fno-common
-I/pool/sources/12-STABLE/src/lib/msun/x86
-I/pool/sources/12-STABLE/src/lib/msun/ld80
-I/pool/sources/12-STABLE/src/lib/msun/amd64
-I/pool/sources/12-STABLE/src/lib/msun/src
-I/pool/sources/12-STABLE/src/lib/libc/include
-I/pool/sources/12-STABLE/src/lib/libc/amd64   -DNDEBUG -mretpoline -MD
 -MF.depend.e_j1f.po -MTe_j1f.po -std=gnu99 -fstack-protector-strong
-Wsystem-headers -Wno-pointer-sign -Wno-unknown-pragmas -Wno-empty-body
-Wno-string-plus-int -Wno-unused-const-variable
-Wno-tautological-compare -Wno-unused-value -Wno-parentheses-equality
-Wno-unused-function -Wno-enum-conversion -Wno-unused-local-typedef
-Wno-address-of-packed-member -Wno-switch -Wno-switch-enum
-Wno-knr-promoted-parameter -Wno-parentheses  -Qunused-arguments  -c
/pool/sources/12-STABLE/src/lib/msun/src/e_j1f.c -o e_j1f.po ---
all_subdir_rescue ---
/pool/sources/12-STABLE/src/bin/cp/utils.c:517:14: error: member
reference base type 'void' is not a structure or union aclp =
&acl->ats_acl; ~~~^ ~~~~~~~
/pool/sources/12-STABLE/src/bin/cp/utils.c:518:11: error: incomplete
definition of type 'struct acl' if (aclp->acl_cnt != 0 &&
aclsetf(dest_dir, ~~~~^
/pool/sources/12-STABLE/src/bin/cp/utils.c:468:9: note: forward
declaration of 'struct acl' struct acl *aclp; ^ 2 errors generated. ***
[/pool/sources/12-STABLE/src/bin/cp/utils.o] Error code 1

make[6]: stopped in
/pool/nanobsd/amd64/ALERICH_12-STABLE_amd64/pool/sources/12-STABLE/src/amd64.amd64/rescue/rescue
1 error

make[6]: stopped in
/pool/nanobsd/amd64/ALERICH_12-STABLE_amd64/pool/sources/12-STABLE/src/amd64.amd64/rescue/rescue
*** [rescue] Error code 2

make[5]: stopped in /pool/sources/12-STABLE/src/rescue/rescue
1 error

make[5]: stopped in /pool/sources/12-STABLE/src/rescue/rescue