bug: 3.22 ENVIRONMENT_MODIFICATION only keeps new value instead of appending
When modifying environment variables, either those existing in the operating system beforehand or those set by test property ENVIRONMENT, the ENVIRONMENT_MODIFICATION append operations overwrite instead of appending. I made a Git repo so I could try it on different machines easily: https://github.com/scivision/cmake-environment-modification
Suppose var1 = "/opt/hello" is previously set environment variable and val2 = "/opt/goodbye" is desired to append to it.
- cmake_list_append: expect /opt/hello;/opt/goodbye
- path_list_append: expect /opt/hello:/opt/goodbye (on Unix-like)
- string_append: exptect /opt/hello/opt/goodbye
In those three cases, instead I just get /opt/goodbye.