Downgrading Subversion from 1.8 to 1.7 in MacPorts

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bash-3.2# cd /tmp
bash-3.2# svn co http://svn.macports.org/repository/macports/trunk/dports/devel/subversion --revision 108493
A    subversion/files
A    subversion/files/patch-Makefile.in.diff
A    subversion/files/patch-osx_unicode_precomp.diff
A    subversion/files/config_impl.h.patch
A    subversion/files/servers.default
A    subversion/Portfile
Ausgecheckt, Revision 108493.
bash-3.2# cd subversion/
bash-3.2# port install
--->  Computing dependencies for subversion
--->  Fetching archive for subversion
--->  Attempting to fetch subversion-1.7.10_1.darwin_12.x86_64.tbz2 from http://mse.uk.packages.macports.org/sites/packages.macports.org/subversion
--->  Attempting to fetch subversion-1.7.10_1.darwin_12.x86_64.tbz2.rmd160 from http://mse.uk.packages.macports.org/sites/packages.macports.org/subversion
...
--->  Scanning binaries for linking errors: 100.0%
--->  No broken files found.
bash-3.2# port installed subversion
The following ports are currently installed:
  subversion @1.7.10_1
  subversion @1.8.1_1 (active)
bash-3.2# port activate subversion @1.7.10_1
--->  Computing dependencies for subversion
--->  Deactivating subversion @1.8.1_1
--->  Cleaning subversion
--->  Activating subversion @1.7.10_1
--->  Cleaning subversion