SPC p f打开的文件，使用SPC TAB，切换出去后，再按一次，切换不回来了。SPC p b 列表里面有，SPC b b列表里面没有。
有个github issue有和我一样的问题。
I also found out that alternate-buffer doesn’t work with buffer switch off from buffer opened by counsel-projectile-find-file. Simply speaking, when I open a buffer with counsel-projectile-find-file, I can switch back to the previous buffer successfully but I could not switch back to buffer opened by projectile. It feels like the buffer opened by projectile never got “remembered”.