unmatch5 ~ # ply 'BEGIN { printf("Hello ply!"); } kretprobe:vfs_read { @["size"] = quantize(retval); }' -d
debug: ir_bpf_generate: v0 -> r2
debug: ir_bpf_generate: v1 -> r6
debug: ir_bpf_generate: v0 -> r6
debug: unlimited memlock
debug: writing xprobe: p:ply1345/p2ae8a2af40_ply_6506 /usr/sbin/ply:6506
error: BEGIN: Unable to attach xprobe: Invalid argument
ERR:-22



on amd64:

#  ply 'BEGIN { printf("Hello ply!"); } kretprobe:vfs_read { @["size"] = quantize(retval); }' -d
1: error: syntax error, unexpected IDENT, expecting PSPEC
ERR:-22