Use bazel as build system

[symbiont-stevan-andjelkovic]

Currently go code can be built and tested using bazel. Other bazel related tasks:

• Use bazel to build and test python (ldfi);
• Use bazel to build and test clojure (checker, scheduler);
• Use bazel to build uberjar and later GraalVM native image;
  • Fix problem with GraalVM image not finding clojure.core libraries at run-time for checker. Fixed in: bazel(checker): make it build and run on linux #161;
  • Fix build on MacOS. rules_graal don't support $location substitutions nor C dependencies, so currently the path to zlib on linux is hardcoded.
• Use bazel to build and test Haskell code (ldfi2);
  • Fix problem with MacOS 11.2.2 Big Sur not fiding C libraries: haskell_cabal_library, cabalopts and --extra-{include,lib}-dirs tweag/rules_haskell#1500;
  • Fix linking issue to z3. ldd ./bazel-bin/src/ldfi2/ldfi2 shows libz3.so => /home/.../detsys-testkit/./bazel-bin/src/ldfi2/../../_solib_k8/_U@haskell_Uz3_S_S_Clibz3___Ulib/libz3.so but after nix-env -if default.nix then ldd $(which detsys-ldfi) says libz3.so => not found (note that when ldfi2 is built with nix we don't get this problem). Fixed in Ldfi libz3 #192.
• Use bazel in combination with nix (rules_nixpkgs);
• The --version flag doesn't work on Golang binaries built by bazel;
• The --version flag doesn't work on Clojure binaries built by bazel. Fixed in bazel(scheduler): make passing --version flag work #205;
• The --version flag doesn't work on Haskell binaries built by bazel. Fixed in bazel ldfi2 version #198;
  • https://stackoverflow.com/questions/49879399/bazel-how-to-access-workspace-status-variables-in-skylark
  • https://stackoverflow.com/questions/50648052/how-can-i-build-custom-rules-using-the-output-of-workspace-status-command
• Figure out where to store db's migration files in the bazel build;
• Fix Caused by: java.lang.Exception: No native library found for os.name=Linux, os.arch=x86_64, paths=[] problem for checker in the bazel build;
• Fix panic: no such function: json_extract problem for debugger with bazel build;
• Use bazel from within nix-build: Is buildBazelPackage from nixpkgs supposed to work? tweag/rules_nixpkgs#73 (will this not ruin the bazel caching?);
• Package up all detsys binaries built by bazel using nix-build: nix: package up all binaries #151;
• Do a nix post-install check on the packaged up binaries to ensure that they are all of the same version;
• Figure out how to use bazel on CI;
• Figure out how to write integration tests using detsys with bazel;
• Make it easy to reproduce/rebuild all the components to some specific version (that was used in some test run, so that that test run could be reproduced);
• Can we package up all binaries in a .deb or brew tarball using nix? (what happens to system dependencies e.g. libz3?)
• Document how to use bazel for development vs nix for packaging.

[symbiont-stevan-andjelkovic]

python support was added in #101.

[symbiont-stevan-andjelkovic]

nix support was added in #97.

[symbiont-stevan-andjelkovic]

Haskell support was added in #140 and #141.

[symbiont-stevan-andjelkovic]

Clojure/java support was added in #143 and #145.

[symbiont-stevan-andjelkovic]

GraalVM native image compilation was added in #147.

Note that this partially reverts #143 and #145 by using griffinbank/rules_clojure rather than simuons/rules_clojure. The former is a fork of the later which reuses as much of java_rules as possible, and graal_rules expect java_rules as input.