Commit graph

17 commits

Author SHA1 Message Date
Eelco Dolstra 7d38060a0d Support non-x86_64-linux system types in flakes
A command like

  $ nix run nixpkgs#hello

will now build the attribute 'packages.${system}.hello' rather than
'packages.hello'. Note that this does mean that the flake needs to
export an attribute for every system type it supports, and you can't
build on unsupported systems. So 'packages' typically looks like this:

  packages = nixpkgs.lib.genAttrs ["x86_64-linux" "i686-linux"] (system: {
    hello = ...;
  });

The 'checks', 'defaultPackage', 'devShell', 'apps' and 'defaultApp'
outputs similarly are now attrsets that map system types to
derivations/apps. 'nix flake check' checks that the derivations for
all platforms evaluate correctly, but only builds the derivations in
'checks.${system}'.

Fixes #2861. (That issue also talks about access to ~/.config/nixpkgs
and --arg, but I think it's reasonable to say that flakes shouldn't
support those.)

The alternative to attribute selection is to pass the system type as
an argument to the flake's 'outputs' function, e.g. 'outputs = { self,
nixpkgs, system }: ...'. However, that approach would be at odds with
hermetic evaluation and make it impossible to enumerate the packages
provided by a flake.
2019-10-15 18:16:29 +02:00
Emilio Karakey d24bfe29a1 deleted comment 2019-10-07 18:28:10 -05:00
Eelco Dolstra 780c1a8f27
nix dev-shell: Ignore $NIX_LOG_FD 2019-10-02 10:52:56 +02:00
Eelco Dolstra 9b9de3a5e3
nix dev-shell: Improve environment handling
Only variables that were marked as exported are exported in the dev
shell. Also, we no longer try to parse the function section of the env
file, fixing

  $ nix dev-shell
  error: shell environment '/nix/store/h7ama3kahb8lypf4nvjx34z06g9ncw4h-nixops-1.7pre20190926.4c7acbb-env' has unexpected line '/^[a-z]?"""/ {'
2019-09-27 17:01:25 +02:00
Eelco Dolstra 662db921e2
nix dev-shell: Set dontAddDisableDepTrack 2019-08-09 18:51:52 +02:00
Eelco Dolstra 336afe4d5f
nix dev-shell: Set IN_NIX_SHELL in the derivation
This ensures that stdenv / setup hooks take $IN_NIX_SHELL into
account. For example, stdenv only sets
NIX_SSL_CERT_FILE=/no-cert-file.crt if we're not in a shell.
2019-07-26 20:09:44 +02:00
Eelco Dolstra aa82f8b2d2
nix dev-shell: Make it possible to enter a profile
For example:

  $ nix dev-shell --profile /tmp/my-shell dwarffs
  (later)
  $ nix dev-shell /tmp/my-shell
2019-07-12 16:36:34 +02:00
Eelco Dolstra 731bc65ec0
Refactor a bit 2019-07-12 16:16:27 +02:00
Eelco Dolstra 7ba928116e
nix dev-shell: Add --profile flag
This is useful to prevent the shell environment from being
garbage-collected.
2019-07-12 16:10:58 +02:00
Eelco Dolstra a0de58f471
Make subcommand construction in MultiCommand lazy 2019-06-18 16:25:31 +02:00
Eelco Dolstra 156e3a9daa
nix dev-shell: Ignore SSL_CERT_FILE 2019-05-11 01:50:28 +02:00
Eelco Dolstra cb5ebc5c11
nix dev-shell: Keep $TERM 2019-05-08 17:07:35 +02:00
Eelco Dolstra 7ba0f98e64 nix dev-shell: Less purity 2019-05-02 21:28:52 +02:00
Eelco Dolstra 8ec77614f6 Move createTempFile to libutil 2019-05-02 21:28:41 +02:00
Eelco Dolstra dea18ff999 nix dev-shell: Execute shellHook 2019-05-02 21:13:19 +02:00
Eelco Dolstra 2919c496ea nix dev-shell: Use 'provides.devShell' by default
Thus

  $ nix dev-shell

will now build the 'provides.devShell' attribute from the flake in the
current directory. If it doesn't exist, it falls back to
'provides.defaultPackage'.
2019-05-02 21:10:13 +02:00
Eelco Dolstra 2b8c63f303 Add 'nix dev-shell' and 'nix print-dev-env' command
'nix dev-shell' is intended to replace nix-shell. It supports flakes,
e.g.

  $ nix dev-shell nixpkgs:hello

starts a bash shell providing an environment for building 'hello'.

Like Lorri (and unlike nix-shell), it computes the build environment
by building a modified top-level derivation that writes the
environment after running $stdenv/setup to $out and exits. This
provides some caching, so it's faster than nix-shell in some cases
(especially for packages with lots of dependencies, where the setup
script takes a long time).

There also is a command 'nix print-dev-env' that prints out shell code
for setting up the build environment in an existing shell, e.g.

  $ . <(nix print-dev-env nixpkgs:hello)

https://github.com/tweag/nix/issues/21
2019-05-02 20:22:14 +02:00