"function may return address of local variable" error with gcc 10.1.1

[jrfondren]

../../../../jsrc/viavx.c: In function 'jtindexofsub':
cc1: warning: function may return address of local variable [-Wreturn-local-addr]
In file included from ../../../../jsrc/j.h:1000,
                 from ../../../../jsrc/viavx.c:8:
../../../../jsrc/viavx.c:1652:71: note: declared here
 1652 | tindexofsub(J jt,I mode,A a,A w){PROLOG(0079);A h=0,z;fauxblockINT(zfaux,1,0);
      |                                                                    ^~~~~

../../../../jsrc/ja.h:363:31: note: in definition of macro 'fauxblockINT'
  363 | #define fauxblockINT(z,n,r) I z[(AKXR(r)>>LGSZI)+(n)]   // define a block, big
enough to hold n atoms at rank r, for use in fauxINT
      |                               ^

shown as a warning here as I passed -Wno-error=return-local-addr after -Werror in the build scripts, to get it to compile.
This error is seen with gcc version 10.1.1 20200507 (Red Hat 10.1.1-1) (GCC) , on Fedora 32 (earlier Fedora versions with earlier gcc versions don't complain about this code).