Because of this one reason, build always fails...Any ideas about what I could try?
EDIT: the solution is to open the xcworkspace instead of the xcproject!
Have the same issue.
What I did with the help of https://premium.wpmudev.org/forums/topic/anybody-solved-this-linker-command-failed-with-exit-code-1 and Adlair Cerecedo-Mendez
Every time you change your architecture (simulator, device or for archive(Generic iOS Device)) you must do the above step: namely, manually build each libraries by selecting them in your scroll list one by one, and only than build and run your main project.
Seems a bit WTF, but it is the only way I resolve this issue...