daemon: Run 'guix substitute' directly and assume a single substituter.

The daemon had a mechanism that allows it to handle a list of
substituters and try them sequentially; this removes it.

* nix/scripts/substitute.in: Remove.
* nix/local.mk (nodist_pkglibexec_SCRIPTS): Remove.
* config-daemon.ac: Don't output 'nix/scripts/substitute'.
* nix/libstore/build.cc (SubstitutionGoal)[subs, sub, hasSubstitute]:
Remove.
[tryNext]: Make private.
(SubstitutionGoal::SubstitutionGoal, SubstitutionGoal::init): Remove now
unneeded initializers.
(SubstitutionGoal::tryNext): Adjust to assume a single substituter: call
'amDone' upfront when we couldn't find substitutes.
(SubstitutionGoal::tryToRun): Adjust to run 'guix substitute' via
'settings.guixProgram'.
(SubstitutionGoal::finished): Call 'amDone(ecFailed)' upon failure
instead of setting 'state' to 'tryNext'.
* nix/libstore/globals.hh (Settings)[substituters]: Remove.
* nix/libstore/local-store.cc (LocalStore::~LocalStore): Adjust to
handle a single substituter.
(LocalStore::startSubstituter): Remove 'path' parameter.  Adjust to
invoke 'settings.guixProgram'.  Don't refer to 'run.program', which no
longer exists.
(LocalStore::querySubstitutablePaths): Adjust for 'runningSubstituters'
being a singleton instead of a list.
(LocalStore::querySubstitutablePathInfos): Likewise, and remove
'substituter' parameter.
* nix/libstore/local-store.hh (RunningSubstituter)[program]: Remove.
(LocalStore)[runningSubstituters]: Remove.
[runningSubstituter]: New field.
[querySubstitutablePathInfos]: Remove 'substituter' parameter.
[startSubstituter]: Remove 'substituter' parameter.
* nix/nix-daemon/guix-daemon.cc (main): Remove references to
'settings.substituters'.
* nix/nix-daemon/nix-daemon.cc (performOp): Ignore the user's
"build-use-substitutes" value when 'settings.useSubstitutes' is false.

1 files changed, 0 insertions, 5 deletions

diff --git a/nix/libstore/globals.hh b/nix/libstore/globals.hh
index 0d9315a41a..0069c85956 100644
--- a/nix/libstore/globals.hh
+++ b/nix/libstore/globals.hh
@@ -115,11 +115,6 @@ struct Settings {
        means infinity.  */
     time_t buildTimeout;
 
-    /* The substituters.  There are programs that can somehow realise
-       a store path without building, e.g., by downloading it or
-       copying it from a CD. */
-    Paths substituters;
-
     /* Whether to use build hooks (for distributed builds).  Sometimes
        users want to disable this from the command-line. */
     bool useBuildHook;