Subversion Repositories shark

Error running this command: /usr/local/bin/svn --non-interactive --config-dir /tmp log --xml --verbose -r 975:1 'file:///home/shark/svn/shark/tags/rel_1_5_beta1/mkf/makefile.libc@975' --limit 2
svn: E160013: File not found: revision 975, path '/shark/tags/rel_1_5_beta1/mkf/makefile.libc'