After removing WARNS?=3 from the Makefile, the following warnings came into the picture:
* -Wmissing-variable-declarations
The global variables should've been static, since traceroute6 only has one file.
* -Wcast-align
Fixing this error would've required creating many local variables on the stack since the error had many instances, hence -Wno-cast-align was added to the Makefile.
*-Wincompatible-pointer-types-discards-qualifiers
I created 2 new variables, to fix this problem, namely ipssp_inbypass and ipssp_outbypass
* -Wshadow
I gave new names to the variables which were being shadowed to deal with this error