$ git log -1 rbx-wip -- ext/kgio/read_write.c
found last record of `ext/kgio/read_write.c' in the following commit:
806c366 split read_write.c into {read,write,writev}.c (2013-11-21)
git clone git://yhbt.net/kgio.git
git clone https://yhbt.net/kgio.git