diff --git a/.travis.yml b/.travis.yml
index f3c92a8..530b4e6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,9 @@
+os: osx
 language: node_js
 node_js:
 - '6'
 script: npm run nexe-build
 env:
-  global:
-    secure: LyC6djYqPfPKz5gHILES9JmSRxQ+ntKOcoaZNM5WID0+gogUoXZBhcmmtvq9RnMpFZN3pYujY6LB5iy7QS2seGjg+feyewNKI30yIK6N9ulJyZZKmrJVDdRx4wvl8YVTkttjcJFkanDGa6zRvFfFDKx/iIdcWLEpnqR/WO1ppf8=
+  - secure: LyC6djYqPfPKz5gHILES9JmSRxQ+ntKOcoaZNM5WID0+gogUoXZBhcmmtvq9RnMpFZN3pYujY6LB5iy7QS2seGjg+feyewNKI30yIK6N9ulJyZZKmrJVDdRx4wvl8YVTkttjcJFkanDGa6zRvFfFDKx/iIdcWLEpnqR/WO1ppf8=
+notifications:
+  email: false
diff --git a/.vscode/settings.json b/.vscode/settings.json
index cc468c9..21d9a88 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -3,6 +3,7 @@
   "prettier.semi": false,
   "prettier.singleQuote": true,
   "prettier.typescriptEnable": ["typescript"],
+  "editor.trimAutoWhitespace": true,
   "files.exclude": {
     "**/.git": true,
     "**/.svn": true,
diff --git a/circle.yml b/circle.yml
index 3c14fff..3590eff 100644
--- a/circle.yml
+++ b/circle.yml
@@ -1,3 +1,8 @@
+machine:
+  node:
+    version: 6.11.2
+  services:
+    - docker
 test:
   override:
     - npm run nexe-build
diff --git a/src/compiler.ts b/src/compiler.ts
index 2564272..c820bc6 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -135,7 +135,11 @@ export class NexeCompiler {
   }
 
   private async _fetchPrebuiltBinaryAsync(target: NexeTarget) {
-    const githubRelease = await getLatestGitRelease()
+    const githubRelease = await getLatestGitRelease({
+      headers: {
+        'User-Agent': 'nexe (https://www.npmjs.com/package/nexe)'
+      }
+    })
     const assetName = target.toString()
     const asset = githubRelease.assets.find(x => x.name === assetName)
 
diff --git a/tasks/build.ts b/tasks/build.ts
index c1ae17d..1f5aac9 100644
--- a/tasks/build.ts
+++ b/tasks/build.ts
@@ -12,13 +12,16 @@ import got = require('got')
 const env = process.env,
   branchName = env.CIRCLE_BRANCH || env.APPVEYOR_REPO_BRANCH || env.TRAVIS_BRANCH || '',
   isScheduled = Boolean(env.APPVEYOR_SCHEDULED_BUILD || env.NEXE_TRIGGERED),
-  isLinux = Boolean(env.TRAVIS),
+  isLinux = Boolean(env.CIRCLECI),
   isWindows = Boolean(env.APPVEYOR),
-  isMac = Boolean(env.CIRCLECI),
+  isMac = Boolean(env.TRAVIS),
   isPullRequest = Boolean(env.CIRCLE_PR_NUMBER)
     || Boolean(env.APPVEYOR_PULL_REQUEST_NUMBER) 
     || Boolean(env.TRAVIS_PULL_REQUEST_BRANCH),
-  headers = { 'Authorization': 'token ' + env.GITHUB_TOKEN }
+  headers = { 
+    'Authorization': 'token ' + env.GITHUB_TOKEN,
+    'User-Agent': 'nexe (https://www.npmjs.com/package/nexe)'
+  }
 
 if (require.main === module) {
   if (!isPullRequest) {
@@ -57,7 +60,7 @@ async function build () {
       options = {
         empty: true,
         build: true,
-        target, //FIXME
+        target,
         output
       }
     
@@ -78,7 +81,8 @@ async function build () {
         body: await readFileAsync(output),
         headers: {
           'Authorization': 'token ' + env.GITHUB_TOKEN,
-          'Content-Type': 'application/octet-stream'
+          'Content-Type': 'application/octet-stream',
+          'User-Agent': 'nexe (https://www.npmjs.com/package/nexe)'
         }
       })
       console.log(target + ' uploaded.')
diff --git a/tasks/ci.ts b/tasks/ci.ts
index e4ddd7c..57ee3a1 100644
--- a/tasks/ci.ts
+++ b/tasks/ci.ts
@@ -3,7 +3,7 @@ import got = require('got')
 import * as assert from 'assert'
 const { env } = process
 
-export function triggerDockerBuild(release: NexeTarget, branch: string) {
+export function triggerMacBuild(release: NexeTarget, branch: string) {
   assert.ok(env.TRAVIS_TOKEN)
   const travis = `https://api.travis-ci.org/repo/nexe%2Fnexe/requests`
   return got(travis, {
@@ -14,7 +14,7 @@ export function triggerDockerBuild(release: NexeTarget, branch: string) {
         config: {
           merge_mode: 'deep_merge',
           env: {
-            NEXE_VERSION: release
+            NEXE_VERSION: release.toString()
           }
         }
       }
@@ -26,7 +26,7 @@ export function triggerDockerBuild(release: NexeTarget, branch: string) {
   })
 }
 
-export function triggerMacBuild (release: NexeTarget, branch: string) {
+export function triggerDockerBuild (release: NexeTarget, branch: string) {
   assert.ok(env.CIRCLE_TOKEN)
   const circle = `https://circleci.com/api/v1.1/project/github/nexe/nexe/tree/${branch}?circle-token=${env.CIRCLE_TOKEN}`
   return got(circle, {
diff --git a/tasks/docker.ts b/tasks/docker.ts
index 952fdee..77721d4 100644
--- a/tasks/docker.ts
+++ b/tasks/docker.ts
@@ -1,32 +1,73 @@
 import { NexeTarget } from '../src/target'
-import { writeFileAsync } from '../src/util'
-import exec = require('execa')
+import { writeFileAsync, readFileAsync } from '../src/util'
+import { spawn } from 'child_process'
+import got = require('got')
+import { createWriteStream, WriteStream } from 'fs'
 
-function alpine (target: NexeTarget, nexeVersion: string) {
-  const version = target.version
+function alpine (target: NexeTarget, nexeVersion: string) {  
   return `
-FROM i386/alpine:3.6
+FROM i386/alpine:3.4
 RUN apk add --no-cache curl make gcc g++ binutils-gold python linux-headers paxctl libgcc libstdc++ git vim tar gzip wget
+ENV NODE_VERSION=${target.version}
+ENV NEXE_VERSION=beta
 WORKDIR /
-RUN curl -sSL https://nodejs.org/dist/v${version}/node-v${version}.tar.gz | tar -xz && \
-  cd /node-v${version} && \
+
+RUN curl -sSL https://nodejs.org/dist/v\${NODE_VERSION}/node-v\${NODE_VERSION}.tar.gz | tar -xz && \
+  cd /node-v\${NODE_VERSION} && \
   ./configure --prefix=/usr --fully-static && \
-  make -j$(grep -c ^processor /proc/cpuinfo 2>/dev/null || 1) && \
+  make -j$(getconf _NPROCESSORS_ONLN) && \
   make install && \
   paxctl -cm /usr/bin/node
 
-RUN mkdir nexe_temp && mv node-v${version} nexe_temp/${version}
-RUN npm i nexe@beta -g
-ENV NEXE_TEMP=/nexe_temp
+RUN mkdir /nexe_temp && mv node-v\${NODE_VERSION} /nexe_temp/\${NODE_VERSION} && \
+  npm install -g nexe@\${NEXE_VERSION} && \
+  nexe --build --empty --temp /nexe_temp -c="--fully-static" -o out
+`.trim()
+}
 
-RUN nexe --empty -c="--fully-static" -o /nexe-out`.trim()
+export async function runAsync (command: string, output: WriteStream) {
+  const commands = command.split(/\r?\n/)
+    .filter(x => x.trim())
+    .map(x => x.trim().split(' '))
+  const sequence = Promise.resolve()
+  for (const command of commands) {
+    await new Promise((resolve, reject) => {
+      const cp = spawn(command.shift() as string, command)
+      cp.stderr.pipe(output)
+      cp.stdout.pipe(output)
+      const close = function (this: any, e: Error) {
+        this.kill()
+        e ? reject(e) : resolve()
+      }
+      cp.on('error', (e) => {
+        output.write(e.stack)
+      })
+      .on('close', close)
+      .on('exit', close)
+    })
+  }
 }
 
 export async function runAlpineBuild (target: NexeTarget, nexeVersion: string) {
   await writeFileAsync('Dockerfile', alpine(target, nexeVersion))
-  const option = { stido: 'inherit' } as any
-  await exec('docker', ['build', '-t', 'nexe-alpine', '.'], option)
-  await exec('docker', ['run', '--name', 'nexe', 'nexe-alpine'], option)
-  await exec('docker', ['cp', 'nexe:/nexe-out', 'out'], option)
-  await exec('docker', ['rm', 'nexe'], option)
+  const outFilename = 'nexe-alpine-build-log.txt'
+  const output = createWriteStream(outFilename)
+  try {
+    await runAsync(`
+    docker build -t nexe-alpine .
+    docker run -d --name nexe nexe-alpine sh
+    docker cp nexe:/out out
+    docker rm nexe
+  `, output)
+  } catch(e) {
+    console.log(e)
+  } finally {
+    output.close()
+    await got(`https://transfer.sh/${Math.random().toString(36).substring(2)}.txt`, {
+      body: await readFileAsync(outFilename),
+      method: 'PUT'
+    })
+    .then(x => console.log(x.body))
+    .catch(e => console.log('Error posting log', e))
+  }
 }