No package 'x11' found

[Kai2020-hello]

I tried to install jskeus via homebrew and got error below.
How can I solve this problem?

checking GL/gl.h presence... yes
checking for GL/gl.h... yes
checking for glBegin in -lGL... yes
checking for GLW... no
configure: error: Package requirements (x11 xt) were not met:

No package 'x11' found
No package 'xt' found

[k-okada]

we're checking if our source is able to compile on OSX on travis, so please compare your log with https://travis-ci.org/euslisp/jskeus/jobs/542140927 and try to find what is missing.

…

-- ◉ Kei Okada 2019年6月12日(水) 17:07 Hanpp张 <notifications@github.com>:

I tried to install jskeus via homebrew and got error below. How can I solve this problem? checking GL/gl.h presence... yes checking for GL/gl.h... yes checking for glBegin in -lGL... yes checking for GLW... no configure: error: Package requirements (x11 xt) were not met: No package 'x11' found No package 'xt' found — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#544?email_source=notifications&email_token=AADYNXDDWZW4EPGP3VL5AFDP2CVE3A5CNFSM4HXGMHU2YY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45C7NFSM4GY7ZZDQ>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AADYNXGOATZXEBBUKZ7IB2TP2CVE3ANCNFSM4HXGMHUQ> .