ocaml+twt not found

[cha1n]

opam install ocaml+twt
[ERROR] No package named ocaml+twt found.

opam --version
2.0~alpha5

when i use version 1.2.2, it still tell No package named ocaml+twt found.

[cha1n]

i solved this

opam install ocaml-twt

but i donnot know why

[zpspring]

I do like you suggest.
opam install batteries ocaml-twt gsl.
Correctly installed.

Then,
cd PhyloCSF
make
But it does not work.

make -C lib/CamlPaml reinstall
make[1]: 正在进入目录 /home/zhongpei/PhyloCSF/lib/CamlPaml' make uninstall make[2]: 正在进入目录/home/zhongpei/PhyloCSF/lib/CamlPaml'
ocamlfind remove CamlPaml
make[2]: ocamlfind：命令未找到
make[2]: *** [uninstall] 错误 127
make[2]:正在离开目录 /home/zhongpei/PhyloCSF/lib/CamlPaml' make[1]: *** [reinstall] 错误 2 make[1]:正在离开目录/home/zhongpei/PhyloCSF/lib/CamlPaml'
make: *** [CamlPaml] 错误 2

Could you help me solve this problem?

[cha1n]

仔细看错误提示啊哥们