前景：在写单元测试的时候，利用gomonkey框架打桩方法函数的时候，出现了如下问题：
Line 81: - permission denied goroutine 13 [running]: /Users/wuhao/go/pkg/mod/github.com/smartystreets/goconvey@v1.6.4/convey/reporting/reports.go:148 +0x6d /Users/wuhao/go/pkg/mod/github.com/smartystreets/goconvey@v1.6.4/convey/reporting/reports.go:121 +0x70 /Users/wuhao/go/pkg/mod/github.com/smartystreets/goconvey@v1.6.4/convey/context.go:235 +0x137
原因如下(属实没看懂)：
Your problem is caused by changes of the linker (ld64) in macOS Catalina. The default value of the max_prot attribute of the __TEXT segment in the Mach-O header has been changed.
Previously max_prot default value was 0x7 (PROT_READ | PROT_WRITE | PROT_EXEC).
The default value has now been changed to 0x5 (PROT_READ | PROT_EXEC)
This means that mprotect cannot make any region that resides within __TEXT writable.
In theory, this should be resolved by providing the linker flag -segprot __TEXT rwx rx, but this is not the case. Since Catalina, the max_prot field is ignored. Instead, max_prot is set to the value of init_prot (see here).
To top it all off, init_prot cannot be set to rwx either due to macOS refusing to execute a file which has a writable __TEXT(init_prot) attribute.
解决方案1:
1.将测试功能编译为一个临时二进制文件
$ go test -c -o<*_test文件>
2.通过dd命令将二进制文件修改为set __TEXT(max_prot)到0x7:
$ printf 'x07' | dd of=bs=1 seek=160 count=1 conv=notrunc
3.运行 二进制文件
缺点：每次改动都要重新编译，较为麻烦，且开发效率低下
解决方案2:
1.使用docker镜像,将自己的/Users/admin/go下的文件映射到docker中的/go
docker run -it --rm -v /Users/go:/go --privileged docker.io/golang bash
2.运行go test <*_test文件>
缺点：找不出更好的方法了～
