my clang is in /usr/bin
in customize group，company-c-headers，my directory is /usr/bin
the message error is ：
clang failed with error 1: /usr/bin/clang -fsyntax-only -Xclang -code-completion-macros -x c++ -Xclang -code-completion-at=-:7:9 -
user-error: Cannot complete at point
help me！
company-c-headers install success。 my config is： (require 'company-c-headers) (add-to-list 'company-backends 'company-c-headers)
my clang is in /usr/bin in customize group，company-c-headers，my directory is /usr/bin
the message error is ： clang failed with error 1: /usr/bin/clang -fsyntax-only -Xclang -code-completion-macros -x c++ -Xclang -code-completion-at=-:7:9 - user-error: Cannot complete at point help me！