060-rclk sometimes fails with routing conflicts

[litghost]

Example:

2020-07-20T19:40:10 - xczu3eg-sfvc784-1-e/060-rclk-seed     - 3h01m: ERROR: [DRC RTSTAT-6] Partial route conflicts: 2 net(s) have a partial conflict. The problem bus(es) and/or net(s) are clk_IBUF[4]_inst/O, GLOBAL_LOGIC1.
2020-07-20T19:40:10 - xczu3eg-sfvc784-1-e/060-rclk-seed     - 3h01m: ERROR: [Vivado 12-1345] Error(s) found during DRC. Bitgen not run.
2020-07-20T19:40:10 - xczu3eg-sfvc784-1-e/060-rclk-seed     - 3h01m: make[3]: *** [build/specimen_371/design.dcp] Error 1
2020-07-20T19:40:10 - xczu3eg-sfvc784-1-e/060-rclk-seed     - 3h01m: make[2]: *** [run] Error 2