oba $$ not working with fat machos

[trufae]

$ r2 -n /bin/ls
 -- Beer in mind.
[0x00000000]> oba $$
[0x00000000]> ob
^D
0$ cp /bin/ls .
0$ rabin2 -x ls
ls.fat/ls.x86_64.0 created (48112)
ls.fat/ls.arm_64.1 created (89088)
0$ r2 ls.fat/ls.arm_64.1
[0x100003a58]> q
0$ r2 -n ls.fat/ls.arm_64.1
 -- You look great, by the way. Very healthy
[0x00000000]> oba $$
[0x00000000]> ob
* 0 3 arm-64 ba:0x00000000 sz:89088 ls.fat/ls.arm_64.1
[0x00000000]>