lix/src/nix/build.cc
Georges Dubus bc6e7ca046 Don't use read-only mode for nix build --dry-run
In dry run mode, new derivations can't be create, so running the command on anything that has not been evaluated before results in an error message of the form `don't know how to build these paths (may be caused by read-only store access)`.

For comparison, the classical `nix-build --dry-run` doesn't use read-only mode.

Closes #1795

(cherry picked from commit 54525682df707742e58311c32e9c9cb18de1e31f)
2021-09-02 14:50:19 +02:00

90 lines
2.8 KiB
C++

#include "eval.hh"
#include "command.hh"
#include "common-args.hh"
#include "shared.hh"
#include "store-api.hh"
#include "local-fs-store.hh"
#include <nlohmann/json.hpp>
using namespace nix;
struct CmdBuild : InstallablesCommand, MixDryRun, MixJSON, MixProfile
{
Path outLink = "result";
BuildMode buildMode = bmNormal;
CmdBuild()
{
addFlag({
.longName = "out-link",
.shortName = 'o',
.description = "Use *path* as prefix for the symlinks to the build results. It defaults to `result`.",
.labels = {"path"},
.handler = {&outLink},
.completer = completePath
});
addFlag({
.longName = "no-link",
.description = "Do not create symlinks to the build results.",
.handler = {&outLink, Path("")},
});
addFlag({
.longName = "rebuild",
.description = "Rebuild an already built package and compare the result to the existing store paths.",
.handler = {&buildMode, bmCheck},
});
}
std::string description() override
{
return "build a derivation or fetch a store path";
}
std::string doc() override
{
return
#include "build.md"
;
}
void run(ref<Store> store) override
{
auto buildables = build(
getEvalStore(), store,
dryRun ? Realise::Derivation : Realise::Outputs,
installables, buildMode);
if (json) logger->cout("%s", derivedPathsWithHintsToJSON(buildables, store).dump());
if (dryRun) return;
if (outLink != "")
if (auto store2 = store.dynamic_pointer_cast<LocalFSStore>())
for (const auto & [_i, buildable] : enumerate(buildables)) {
auto i = _i;
std::visit(overloaded {
[&](BuiltPath::Opaque bo) {
std::string symlink = outLink;
if (i) symlink += fmt("-%d", i);
store2->addPermRoot(bo.path, absPath(symlink));
},
[&](BuiltPath::Built bfd) {
for (auto & output : bfd.outputs) {
std::string symlink = outLink;
if (i) symlink += fmt("-%d", i);
if (output.first != "out") symlink += fmt("-%s", output.first);
store2->addPermRoot(output.second, absPath(symlink));
}
},
}, buildable.raw());
}
updateProfile(buildables);
}
};
static auto rCmdBuild = registerCommand<CmdBuild>("build");