drop2.js failing under sharding_passthrough

Error: Printing Stack Trace

    at printStackTrace (src/mongo/shell/utils.js:37:15)

    at doassert (src/mongo/shell/assert.js:6:5)

    at Function.assert.soon (src/mongo/shell/assert.js:110:60)

    at jstests/drop2.js:40:8

    at /mntfast/data/slave/Linux_64bit_Nightly/mongo/jstests/slowNightly/sharding_passthrough.js:142:13

    at Function.Date.timeFunc (src/mongo/shell/types.js:27:17)

    at /mntfast/data/slave/Linux_64bit_Nightly/mongo/jstests/slowNightly/sharding_passthrough.js:141:14

    at Array.forEach (native)

    at /mntfast/data/slave/Linux_64bit_Nightly/mongo/jstests/slowNightly/sharding_passthrough.js:9:7

Wed May 15 10:57:41.745 JavaScript execution failed: assert.soon failed: function () { dropOp = op( true ); return dropOp; }, msg:undefined at src/mongo/shell/assert.js:L7

Wed May 15 10:57:41.745 JavaScript execution failed: Error: error loading js file: jstests/drop2.js at /mntfast/data/slave/Linux_64bit_Nightly/mongo/jstests/slowNightly/sharding_passthrough.js:L142

failed to load: /mntfast/data/slave/Linux_64bit_Nightly/mongo/jstests/slowNightly/sharding_passthrough.js