Firstly, when I try xhemi on pre-possessed longitudinal data, it showed error like this:
Performing left-right swap of labels
TR=2300.00, TE=2.98, TI=900.00, flip angle=9.00
i_ras = (-1, 3.72529e-08, 3.35276e-08)
j_ras = (-2.6077e-08, -3.72529e-09, -1)
k_ras = (-1.78814e-07, 1, 6.98492e-10)
writing to /HD4/symptom_test//subj_02_1.long.s02_base/xhemi/mri/aparc+aseg.mgz...
Wed Dec 20 17:46:35 EST 2017
recon-all -sb subj_02_1.long.s02_base/xhemi -talairach

ERROR: Are you trying to run or re-run a longitudinal time point?
       If so, please specify the following parameters:

       \' -long <tpNid> <templateid> \'

       where <tpNid> is the time point id (SAME as cross sectional
       ID) and <templateid> is the ID created in the -base run.
       The directory <tpNid>.long.<templateid> will be created
       automatically or used for output, if it already exists.