tvl-depot/emacs/.emacs.d/wpc/wpc-nix.el
William Carroll 28af585f3d Include NIX_PATH settings in nix/rebuild-emacs function
I'm currently setting NIX_PATH in ~/briefcase/shell.nix. This means when I call
`nix/rebuild-emacs` from a buffer that is inside the briefcase directory, the
command succeeds because NIX_PATH is properly defined. When I call
`nix/rebuild-emacs` from any other location it fails.

I'm hard-coding the NIX_PATH in this command so that I can call
`nix/rebuild-emacs` from any buffer that is currently active.
2020-03-06 18:45:55 +00:00

79 lines
3.5 KiB
EmacsLisp

;;; wpc-nix.el --- Nix support -*- lexical-binding: t -*-
;; Author: William Carroll <wpcarro@gmail.com>
;;; Commentary:
;; Configuration to support working with Nix.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Dependencies
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; TODO: These may fail at startup. How can I make sure that the .envrc is
;; consulted when Emacs starts?
(prelude/assert (f-exists? (getenv "BRIEFCASE")))
(prelude/assert (f-exists? (getenv "DEPOT")))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Library
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(use-package nix-mode
:mode "\\.nix\\'")
;; TODO(wpcarro): Ensure the sub-process can resolve <briefcase>.
(defun nix/rebuild-emacs ()
"Use nix-env to rebuild wpcarros-emacs."
(interactive)
(start-process "nix-build/<briefcase/emacs>" "*nix-build/<briefcase/emacs>*"
"nix-env"
"-I" (format "nixpkgs=%s" (f-expand "~/nixpkgs"))
"-I" (format "depot=%s" (f-expand "~/depot"))
"-I" (format "briefcase=%s" (f-expand "~/briefcase"))
"-f" "<briefcase>" "-iA" "emacs")
(display-buffer "*nix-build/<briefcase/emacs>*"))
(defun nix/home-manager-switch ()
"Use Nix to reconfigure the user environment."
(interactive)
(start-process "nix/home-manager-switch" "*nix/home-manager-switch*"
"home-manager"
"-I" (format "nixpkgs=%s" (f-expand "~/nixpkgs"))
"-I" (format "home-manager=%s" (f-expand "~/home-manager"))
"switch")
(display-buffer "*nix/home-manager-switch*"))
(defun nix/sly-from-briefcase (attribute)
"Start a Sly REPL configured with a Lisp matching a derivation
from my monorepo.
This function was taken from @tazjin's depot and adapted for my monorepo.
The derivation invokes nix.buildLisp.sbclWith and is built
asynchronously. The build output is included in the error
thrown on build failures."
(interactive "sAttribute: ")
(lexical-let* ((outbuf (get-buffer-create (format "*briefcase-out/%s*" attribute)))
(errbuf (get-buffer-create (format "*briefcase-errors/%s*" attribute)))
(expression (format "let depot = import <depot> {}; briefcase = import <briefcase> {}; in depot.nix.buildLisp.sbclWith [ briefcase.%s ]" attribute))
(command (list "nix-build" "-E" expression)))
(message "Acquiring Lisp for <briefcase>.%s" attribute)
(make-process :name (format "nix-build/%s" attribute)
:buffer outbuf
:stderr errbuf
:command command
:sentinel
(lambda (process event)
(unwind-protect
(pcase event
("finished\n"
(let* ((outpath (s-trim (with-current-buffer outbuf (buffer-string))))
(lisp-path (s-concat outpath "/bin/sbcl")))
(message "Acquired Lisp for <briefcase>.%s at %s" attribute lisp-path)
(sly lisp-path)))
(_ (with-current-buffer errbuf
(error "Failed to build '%s':\n%s" attribute (buffer-string)))))
(kill-buffer outbuf)
(kill-buffer errbuf))))))
(provide 'wpc-nix)
;;; wpc-nix.el ends here