Replace shell.nix with a flake devShell attribute

Dependencies

• [2] AVGER75N release: bump to 19.03
• [3] CCPSI3TP Add flake.nix
• [4] D3MDJONY
• [5] GBCPEGYC Add a .gitignore
• [6] DWQCLOPQ Tweaks for nix-shell
• [7] X7IAG7JT Simplify running nix-shell
• [8] JN7Y4DC2 Add hydra status dd timeboard expression
• [9] UHMUHQMU hydra: fix tarball build, add pre suffix to tarballs
• [10] UBPWXGKF Move build logic for the core hydra package into its own default.nix.
• [11] BAUP4PCK inNixShell considered harmful
• [12] G2ZB6464 first test, not yet in buildprocess
• [13] X27GNHDV * Basic job info in the database.
• [14] 6A6CZ7SC draft manual
• [15] ZL4LHHZF Remove empty files
• [16] ICYJNJWH Revert "Move build logic for the core hydra package into its own default.nix."
• [17] FV2M6MOT hydra: use autoconf/-make
• [18] SAPEZKXH move file and add a basic README
• [19] SAFVRDTK * Put Hydra's dependencies so that they can easily be installed in a
• [20] 6K5PBUUN Use buildEnv to combine Hydra's Perl dependencies
• [21] CLXEECMF * Start putting build results in a database.
• [22] T4LLYESZ * Nix expression for building Hydra.
• [23] NVMDS7GE Add README.md
• [24] SFMN6AFQ * Include a license.

Change contents

• file deletion: shell.nix (----------)
  [4.2]→[4.1165:1198](∅→∅),[4.1198]→[4.1118:1118](∅→∅)
  − (import ./release.nix { shell = true; }).build.x86_64-linux
• edit in flake.nix at line 20
  [3.573]

  [3.573]
  +

  + devShell = (import ./release.nix {

  + hydraSrc = deps.self;

  + nixpkgs = deps.nixpkgs;

  + shell = true;

  + }).build.x86_64-linux;

  +
• replacement in release.nix at line 141
  [2.116]→[2.116:164](∅→∅)
  − NIX_LDFLAGS = [

  − "-lpthread"

  − ];
  [2.116]

  [4.3433]
  + NIX_LDFLAGS = [ "-lpthread" ];