Fixes <https://bugs.gnu.org/29862>.
Reported by Danny Milosavljevic <dannym@scratchpost.org>.
* nix/scripts/list-runtime-roots.in (canonicalize-store-item): Define
'store' with a trailing "/". Have the 'string-prefix?' call match the
'string-drop' call.
This allows running as non-root.
Fixes a regression introduced in b8f59cdc20.
* nix/scripts/list-runtime-roots.in (referenced-files): Handle EACCES in
addition to ENOENT.
Looking at 'addAdditionalRoots' in libstore/gc.cc, it looks like it
should always have been this way. In practice it probably doesn't make
much of a difference.
* nix/scripts/list-runtime-roots.in (canonicalize-store-item): New
procedure.
<top level>: Use it.
This makes things a bit faster (0.8s instead of 1.4s on my laptop).
* nix/scripts/list-runtime-roots.in (lsof-roots): Remove.
(proc-fd-roots): Return the empty list when 'scandir' returns #f.
(referenced-files): New procedure.
Use it at the top level.
* nix/nix-daemon/guix-daemon.cc (GUIX_OPT_NO_BUILD_HOOK): New macro.
(options): Add '--no-build-hook'.
(parse_opt): Handle it.
(main)[HAVE_DAEMON_OFFLOAD_HOOK]: Set 'useBuildHook' by default.
Set $NIX_BUILD_HOOK to our offload hook unless otherwise specified.
[!HAVE_DAEMON_OFFLOAD_HOOK]: Clear 'useBuildHook'.
* pre-inst-env.in: Set and export NIX_BUILD_HOOK.
* nix/scripts/offload.in, guix/scripts/offload.scm: New files.
* guix/ui.scm (show-guix-help)[internal?]: Add "offload".
* config-daemon.ac: Call 'GUIX_CHECK_UNBUFFERED_CBIP'.
Instantiate 'nix/scripts/offload'. Set 'BUILD_DAEMON_OFFLOAD'
conditional, and optionally define 'HAVE_DEAMON_OFFLOAD_HOOK' cpp
macro.
* daemon.am (nodist_pkglibexec_SCRIPTS)[BUILD_DAEMON_OFFLOAD]: Add it.
* Makefile.am (MODULES)[BUILD_DAEMON_OFFLOAD]: Add
'guix/scripts/offload.scm'.
(EXTRA_DIST)[!BUILD_DAEMON_OFFLOAD]: Likewise.
* m4/guix.m4 (GUIX_CHECK_UNBUFFERED_CBIP): New macro.
* doc/guix.texi (Setting Up the Daemon): Move most of the body to...
(Build Environment Setup): ... this. New subsection.
(Daemon Offload Setup): New subsection.
Inspired by <772b70952f...4ddd077bfa>.
* nix/scripts/list-runtime-roots.in (%store-directory): New variable.
(proc-environ-roots): New procedure.
(<top-level>): Use it.
* guix/scripts/substitute-binary.scm: New file.
* Makefile.am (MODULES): Add it.
* nix/scripts/substitute-binary.in: New file.
* config-daemon.ac: Produce nix/scripts/substitute-binary.
* daemon.am (nodist_pkglibexec_SCRIPTS): Add
nix/scripts/substitute-binary.
* guix/store.scm (substitutable-path-info): Use the
`query-substitutable-path-infos' RPC.
* nix/nix-daemon/guix-daemon.cc (main): Honor `NIX_SUBSTITUTERS'.
* pre-inst-env.in: Set `NIX_SUBSTITUTERS'.
* test-env.in: Leave `NIX_SUBSTITUTERS' unchanged. Set
`GUIX_BINARY_SUBSTITUTE_URL, and create
$NIX_STATE_DIR/substituter-data.
Run `guix-daemon' within `./pre-inst-env'.
* tests/store.scm ("substitute query"): New test.
* nix/scripts/list-runtime-roots.in: New file.
* config-daemon.ac: Add `AC_CONFIG_FILES' invocation for it.
* daemon.am (nodist_pkglibexec_SCRIPTS): New variable.
(AM_TESTS_ENVIRONMENT): Define `top_builddir'.
* tests/guix-daemon.sh: Export `NIX_ROOT_FINDER'.
* nix/sync-with-upstream: Substitute the path to the root finder in
libstore/gc.cc.
