"username", "password" are also needed.

One more thing to watch out for is disk writes when nothing changed. During a
normal sync, SyncEvolution updates the "nonce" string on both sides and some
date strings. The amount of modified data is small and typically the file sizes
don't change. However, the .ini files get written anew and then renamed, so the
amount of written data is larger than just the changes. I think the .bfi files
are updated in place, but I need to check.

$ diff -r /home/pohly/.config/syncevolution/pim-manager-google/ 
pim-manager-google/ | diffstat
 /.internal.ini                                                                
          |    2 +-

pim-manager-google/peers/eds/.@pim-manager-google/.synthesis/remote_1_clg_sysynclib_.bfi
|binary

pim-manager-google/peers/eds/.@pim-manager-google/.synthesis/sysynclib_prof.bfi
         |binary

pim-manager-google/peers/eds/.@pim-manager-google/.synthesis/sysynclib_targ.bfi
         |binary
 pim-manager-google/peers/eds/.internal.ini                                    
          |    4 ++--
 pim-manager-google/peers/eds/sources/local/.internal.ini                      
          |    2 +-
 6 files changed, 4 insertions(+), 4 deletions(-)

-rw-r--r-- 1 pohly pallas   44 Aug 27 15:03 .internal.ini
-rw-r--r-- 1 pohly pallas  801 Aug 27 15:39 peers/eds/.internal.ini
-rw-r--r-- 1 pohly pallas 4520 Aug 27 15:39
peers/eds/.@pim-manager-google/.synthesis/remote_1_clg_sysynclib_.bfi
-rw-r--r-- 1 pohly pallas 1780 Aug 27 15:39
peers/eds/.@pim-manager-google/.synthesis/sysynclib_prof.bfi
-rw-r--r-- 1 pohly pallas 1524 Aug 27 15:39
peers/eds/.@pim-manager-google/.synthesis/sysynclib_targ.bfi
-rw-r--r-- 1 pohly pallas  471 Aug 27 15:39
peers/eds/sources/local/.internal.ini

It might be possible to treat the case of "nothing changed" as special and
finish the sync without updating these files.