/usercode/main.swift:10:7: warning: expression implicitly coerced from 'String?' to Any
print(String.init(data: a, encoding: .utf8))
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usercode/main.swift:10:14: note: provide a default value to avoid this warning
print(String.init(data: a, encoding: .utf8))
      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                            ?? <#default value#>
/usercode/main.swift:10:14: note: force-unwrap the value to avoid this warning
print(String.init(data: a, encoding: .utf8))
      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                           !
/usercode/main.swift:10:14: note: explicitly cast to Any with 'as Any' to silence this warning
print(String.init(data: a, encoding: .utf8))
      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                            as Any
swift: /home/buildnode/jenkins/workspace/oss-swift-4.1-package-linux-ubuntu-16_04/swift/lib/SILGen/RValue.cpp:533: void swift::Lowering::RValue::forwardInto(swift::Lowering::SILGenFunction &, swift::SILLocation, swift::Lowering::Initialization *) &&: Assertion `isPlusOne(SGF) && "Can not forward borrowed RValues"' failed.
/usr/bin/swift[0x3f24d54]
/usr/bin/swift[0x3f25096]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x11390)[0x7f582f9c3390]
/lib/x86_64-linux-gnu/libc.so.6(gsignal+0x38)[0x7f582e102428]
/lib/x86_64-linux-gnu/libc.so.6(abort+0x16a)[0x7f582e10402a]
/lib/x86_64-linux-gnu/libc.so.6(+0x2dbd7)[0x7f582e0fabd7]
/lib/x86_64-linux-gnu/libc.so.6(+0x2dc82)[0x7f582e0fac82]
/usr/bin/swift[0xcd7ac0]
/usr/bin/swift[0xccee92]
/usr/bin/swift[0xc5450f]
/usr/bin/swift[0xccf200]
/usr/bin/swift[0xcf6d60]
/usr/bin/swift[0xcf55ab]
/usr/bin/swift[0xcf4e80]
/usr/bin/swift[0xce08fc]
/usr/bin/swift[0xce8a68]
/usr/bin/swift[0xca1799]
/usr/bin/swift[0xc9dd66]
/usr/bin/swift[0xc79460]
/usr/bin/swift[0xc6eff8]
/usr/bin/swift[0xcf6b1a]
/usr/bin/swift[0xcf74c6]
/usr/bin/swift[0xcf620a]
/usr/bin/swift[0xcf55ab]
/usr/bin/swift[0xcf4e80]
/usr/bin/swift[0xce08fc]
/usr/bin/swift[0xcdf3dc]
/usr/bin/swift[0xc74274]
/usr/bin/swift[0xc78307]
/usr/bin/swift[0xc6f45b]
/usr/bin/swift[0xcc12b1]
/usr/bin/swift[0xcc106e]
/usr/bin/swift[0xc8fec5]
/usr/bin/swift[0xc33515]
/usr/bin/swift[0xc32021]
/usr/bin/swift[0xc3221d]
/usr/bin/swift[0x4c27c4]
/usr/bin/swift[0x4beecc]
/usr/bin/swift[0x4778c4]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)[0x7f582e0ed830]
/usr/bin/swift[0x475179]
Stack dump:
0.	Program arguments: /usr/bin/swift -frontend -interpret /usercode/main.swift -disable-objc-interop -I /usr/lib/swift/clang/include/ -I /vendor/SwiftyMath/.build/release/ -I /vendor/swift-package-libbsd/ -module-name main -ldSwiftyMath 
1.	While silgen emitFunction SIL function "@_T04main4UserV6encodeys7Encoder_p2to_tKF".
 for 'encode(to:)' in module 'main'
Aborted (core dumped)