I accidentially typed forward slash two times when specifying connection and got an assert, looks like having two consecutive forward slashes leads to this:

~$ mongo host//
MongoDB shell version: 1.8.0
connecting to: host//
Thu Mar 31 01:28:24 terminate() called in shell, printing stack:
0x80adf16 0xb7716865 0xb77168a2 0xb77169da 0x81132a6 0x81208ae 0x812e82f 0x8120daa 0x8160618 0x81f794e 0x81f905f 0x8202c96 0x81f82d0 0x81be141 0x81be098 0x81bdfa2 0x816c9fd 0x80c60b4 0x81521f7 0x80b1bb4
mongo(_Z11myterminatev+0x56) [0x80adf16]
/usr/lib/libstdc++.so.6 [0xb7716865]
/usr/lib/libstdc++.so.6 [0xb77168a2]
/usr/lib/libstdc++.so.6 [0xb77169da]
mongo(_ZN5mongo9uassertedEiPKc+0xd6) [0x81132a6]
mongo(_ZN5mongo16ConnectionString12_fillServersESs+0x30e) [0x81208ae]
mongo(ZN5mongo16ConnectionStringC1ENS0_14ConnectionTypeERKSsS3+0x7f) [0x812e82f]
mongo(_ZN5mongo16ConnectionString5parseERKSsRSs+0x2fa) [0x8120daa]
mongo(ZN5mongo26mongo_external_constructorEP9JSContextP8JSObjectjPlS4+0xd8) [0x8160618]
mongo(js_Invoke+0xc34) [0x81f794e]
mongo(js_InvokeConstructor+0x295) [0x81f905f]
mongo(js_Interpret+0x9ad5) [0x8202c96]
mongo(js_Execute+0x2f4) [0x81f82d0]
mongo(JS_EvaluateUCScriptForPrincipals+0xa7) [0x81be141]
mongo(JS_EvaluateUCScript+0x43) [0x81be098]
mongo(JS_EvaluateScript+0x6c) [0x81bdfa2]
mongo(_ZN5mongo7SMScope4execERKNS_10StringDataERKSsbbbi+0x11d) [0x816c9fd]
mongo(_ZN5mongo10shellUtils9initScopeERNS_5ScopeE+0xf4) [0x80c60b4]
mongo(_ZN5mongo12ScriptEngine8newScopeEv+0x37) [0x81521f7]
mongo(_Z5_mainiPPc+0x1d04) [0x80b1bb4]