def requestCounter = new AtomicInteger()
        httpBuildCacheServer.addResponder { req, res ->
            requestCounter.incrementAndGet()
            res.sendError(500)
            false
        }
        settingsFile << withHttpBuildCacheServer()

        when:
        withBuildCache().run("customTask", "customTask2")

        then:

                        KeyServer.this.fileHandler("/pks/lookup", KeyServer.this.keyFiles[keyId]).handle(request, response)
                    } else {
                        response.sendError(404, "not found")
                    }
                }
            }
        })
    }

    void registerPublicKey(PGPPublicKey key) {
        String longKeyId = toLongIdHexString(key.keyID)

            void handle(HttpServletRequest request, HttpServletResponse response) {
                response.sendError(304, 'Not Modified')
            }
        })

        then:
        fails 'retrieve'

        failure.assertHasCause('Response 304: Not Modified has no content!')
    }

        and:
        httpBuildCacheServer.addResponder { req, res ->
            if (req.method == "PUT") {
                assert req.getHeader("expect") == "100-continue"
                res.sendError(401)
                false
            } else {
                true
            }
        }

        when:
        executer.withStackTraceChecksDisabled()
        withBuildCache().run "jar"