Do the build on CI using nix.

.travis.yml

@@ -1,60 +1,20 @@
-language: node_js
-node_js:
-- 4
-python: "3.5"
+language: nix
+nix: 2.1.3
 
 script:
-  - meson . ./build --buildtype=debugoptimized -Dgc=true -Dprof=true
-  - cd ./build
-  - ninja
-  - sudo ninja install
-  - cd ../.travis
-  - ulimit -c unlimited -S
-  - npm install
-  # || true so we continue
-  - npm run -s test || RESULT=$?
-  - if [[ ${RESULT} -eq 0 ]]; then exit 0; else for i in $(find ./ -maxdepth 1 -name 'core*' -print); do gdb urbit core* -ex "thread apply all bt" -ex "set pagination 0" -batch; done; fi;
-  - echo "build failed with status code $RESULT"
-  - exit $RESULT
+  - nix-shell --pure --run './scripts/cibuild -Dnix=true'
 
 # Uncomment me if this gets annoying
 #
 # notifications:
 #   email: false
 
-before_install:
-  - wget https://github.com/ninja-build/ninja/releases/download/v1.8.2/ninja-linux.zip
-  - unzip ninja-linux.zip
-  - sudo mv ninja /usr/bin/
-
 install:
-  # pwd: ~/urbit
-  - pip3 install --user -I meson==0.46.1
   - git clone https://github.com/urbit/arvo
   - cd ./arvo
   - git checkout $(cat ../.travis/pin-arvo-commit.txt)
   - cd ..
 
-addons:
-  apt:
-    packages:
-    - python3
-    - python3-pip
-    - libgmp3-dev
-    - libsigsegv-dev
-    - openssl
-    - libssl-dev
-    - libncurses5-dev
-    - automake
-    - autoconf
-    - make
-    - libtool
-    - g++
-    - re2c
-    - libcurl4-gnutls-dev
-    - unzip
-    - gdb
-# before_deploy: "make deb" # TODO
 deploy:
   skip_cleanup: true
   provider: releases

scripts/cibuild

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+
+set -ex
+
+meson . ./build --buildtype=debugoptimized -Dgc=true -Dprof=true "$@"
+
+cd ./build
+
+ninja || true
+
+sudo ninja install
+
+cd ../.travis
+
+ulimit -c unlimited -S
+
+npm install
+
+npm run -s test || RESULT=$?
+
+[[ ${RESULT} -eq 0 ]] && exit 0
+
+for i in $(find ./ -maxdepth 1 -name 'core*' -print)
+do gdb urbit core* -ex "thread apply all bt" -ex "set pagination 0" -batch
+done
+
+echo "build failed with status code $RESULT"
+
+exit $RESULT