Travis CI 找不到头文件

基本上我想学习CMake和GTest。最重要的是，我想尝试CI，我已经将我的简单项目添加到Travis CI和AppVeyor中。该项目在我的本地机器上编译得很好(使用 vs 2017 和 g++ 进行测试，不确定版本，因为我现在不在它附近(以及 AppVeyor 上。

该项目由几个编译为静态库的标头组成，可执行用于"手动测试"静态库和 gtest(目前没有测试，只是一个模板(。结构如下所示：

.
+-- .appveyor.yml
+-- .travis.yml
+-- CMakeLists.txt
+-- main
|   +-- main.cpp [The manual testing exec]
|   +-- CMakeLists.txt
+-- include
|   +-- Utility.h
|   +-- CMakeLists.txt
|   +-- Other header files to compile to static library
+-- test
|   +-- CMakeLists.txt
|   +-- CMakeLists.txt.in
|   +-- testutility
|   |   +-- main.cpp [sample exe file for gtest, not used yet]
|   |   +-- CMakeLists.txt 

在 Travis CI 上构建期间，它找不到静态库的标头。我试过使用 include_directories(".")在主要的CMakeList上。

主要CMake列表.txt

cmake_minimum_required (VERSION 3.1)
project (primlibrary)
enable_testing()
include_directories(".")
add_subdirectory(include)
add_subdirectory(main)
add_subdirectory(test)

特拉维斯 CI 错误消息

CMake Error at include/CMakeLists.txt:12 (add_library):
  Cannot find source file:
    Utility.h
  Tried extensions .c .C .c++ .cc .cpp .cxx .m .M .mm .h .hh .h++ .hm .hpp
  .hxx .in .txx
-- Generating done
-- Build files have been written to: /home/travis/build/SoIAS/PrimLibrary/build
The command "cmake .." exited with 1.
$ make
Scanning dependencies of target prim_library
[  9%] Linking CXX static library libprim_library.a
[  9%] Built target prim_library
Scanning dependencies of target manualtestingapp
[ 18%] Building CXX object main/CMakeFiles/manualtestingapp.dir/main.cpp.o
/home/travis/build/SoIAS/PrimLibrary/main/main.cpp:2:29: fatal error: include/Utility.h: No such file or directory
 #include "include/Utility.h"

并包括/CMakeLists.txt：

set(CMAKE_CXX_STANDARD 14) 
set(CMAKE_CXX_STANDARD_REQUIRED ON) 
set(CMAKE_CXX_EXTENSIONS OFF) 
set(prim_library_srcs  
  ForwardList.h 
  LinkedList.h 
  Utility.h 
  tempfix.cpp 
) 
add_library(prim_library STATIC ${prim_library_srcs}) 
set_target_properties(prim_library PROPERTIES LINKER_LANGUAGE CXX) 
target_include_directories(prim_library PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

CI 和 git 链接：- 特拉维斯CI最后构建- 应用构建- Github

你知道我做错了什么吗？