diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 097ff210a..332c1c43a 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -478,6 +478,17 @@ Path createTempDir(const Path & tmpRoot, const Path & prefix,
}
+std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix)
+{
+ Path tmpl(getEnv("TMPDIR").value_or("/tmp") + "/" + prefix + ".XXXXXX");
+ // Strictly speaking, this is UB, but who cares...
+ AutoCloseFD fd(mkstemp((char *) tmpl.c_str()));
+ if (!fd)
+ throw SysError("creating temporary file '%s'", tmpl);
+ return {std::move(fd), tmpl};
+}
+
+
std::string getUserName()
{
auto pw = getpwuid(geteuid());
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index 7c3a30242..1f85c7c46 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -122,10 +122,6 @@ void deletePath(const Path & path);
void deletePath(const Path & path, unsigned long long & bytesFreed);
-/* Create a temporary directory. */
-Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix",
- bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755);
-
std::string getUserName();
/* Return $HOME or the user's home directory from /etc/passwd. */
@@ -205,6 +201,14 @@ public:
};
+/* Create a temporary directory. */
+Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix",
+ bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755);
+
+/* Create a temporary file, returning a file handle and its path. */
+std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix = "nix");
+
+
class Pipe
{
public:
diff --git a/src/nix/build.cc b/src/nix/build.cc
index 3c9d2df39..0b0762836 100644
--- a/src/nix/build.cc
+++ b/src/nix/build.cc
@@ -5,7 +5,7 @@
using namespace nix;
-struct CmdBuild : MixDryRun, InstallablesCommand
+struct CmdBuild : InstallablesCommand, MixDryRun, MixProfile
{
Path outLink = "result";
@@ -40,6 +40,10 @@ struct CmdBuild : MixDryRun, InstallablesCommand
"To build the build.x86_64-linux attribute from release.nix:",
"nix build -f release.nix build.x86_64-linux"
},
+ Example{
+ "To make a profile point at GNU Hello:",
+ "nix build --profile /tmp/profile nixpkgs.hello"
+ },
};
}
@@ -49,18 +53,19 @@ struct CmdBuild : MixDryRun, InstallablesCommand
if (dryRun) return;
- for (size_t i = 0; i < buildables.size(); ++i) {
- auto & b(buildables[i]);
-
- if (outLink != "")
- for (auto & output : b.outputs)
+ if (outLink != "") {
+ for (size_t i = 0; i < buildables.size(); ++i) {
+ for (auto & output : buildables[i].outputs)
if (auto store2 = store.dynamic_pointer_cast<LocalFSStore>()) {
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), true);
}
+ }
}
+
+ updateProfile(buildables);
}
};
diff --git a/src/nix/command.cc b/src/nix/command.cc
index 442bc6c53..99b24d2a2 100644
--- a/src/nix/command.cc
+++ b/src/nix/command.cc
@@ -2,6 +2,9 @@
#include "store-api.hh"
#include "derivations.hh"
#include "nixexpr.hh"
+#include "profiles.hh"
+
+extern char * * environ;
namespace nix {
@@ -96,4 +99,95 @@ Strings editorFor(const Pos & pos)
return args;
}
+MixProfile::MixProfile()
+{
+ mkFlag()
+ .longName("profile")
+ .description("profile to update")
+ .labels({"path"})
+ .dest(&profile);
+}
+
+void MixProfile::updateProfile(const StorePath & storePath)
+{
+ if (!profile) return;
+ auto store = getStore().dynamic_pointer_cast<LocalFSStore>();
+ if (!store) throw Error("'--profile' is not supported for this Nix store");
+ auto profile2 = absPath(*profile);
+ switchLink(profile2,
+ createGeneration(
+ ref<LocalFSStore>(store),
+ profile2, store->printStorePath(storePath)));
+}
+
+void MixProfile::updateProfile(const Buildables & buildables)
+{
+ if (!profile) return;
+
+ std::optional<StorePath> result;
+
+ for (auto & buildable : buildables) {
+ for (auto & output : buildable.outputs) {
+ if (result)
+ throw Error("'--profile' requires that the arguments produce a single store path, but there are multiple");
+ result = output.second.clone();
+ }
+ }
+
+ if (!result)
+ throw Error("'--profile' requires that the arguments produce a single store path, but there are none");
+
+ updateProfile(*result);
+}
+
+MixDefaultProfile::MixDefaultProfile()
+{
+ profile = getDefaultProfile();
+}
+
+MixEnvironment::MixEnvironment() : ignoreEnvironment(false) {
+ mkFlag()
+ .longName("ignore-environment")
+ .shortName('i')
+ .description("clear the entire environment (except those specified with --keep)")
+ .set(&ignoreEnvironment, true);
+
+ mkFlag()
+ .longName("keep")
+ .shortName('k')
+ .description("keep specified environment variable")
+ .arity(1)
+ .labels({"name"})
+ .handler([&](std::vector<std::string> ss) { keep.insert(ss.front()); });
+
+ mkFlag()
+ .longName("unset")
+ .shortName('u')
+ .description("unset specified environment variable")
+ .arity(1)
+ .labels({"name"})
+ .handler([&](std::vector<std::string> ss) { unset.insert(ss.front()); });
+}
+
+void MixEnvironment::setEnviron() {
+ if (ignoreEnvironment) {
+ if (!unset.empty())
+ throw UsageError("--unset does not make sense with --ignore-environment");
+
+ for (const auto & var : keep) {
+ auto val = getenv(var.c_str());
+ if (val) stringsEnv.emplace_back(fmt("%s=%s", var.c_str(), val));
+ }
+
+ vectorEnv = stringsToCharPtrs(stringsEnv);
+ environ = vectorEnv.data();
+ } else {
+ if (!keep.empty())
+ throw UsageError("--keep does not make sense without --ignore-environment");
+
+ for (const auto & var : unset)
+ unsetenv(var.c_str());
+ }
+}
+
}
diff --git a/src/nix/command.hh b/src/nix/command.hh
index a954a7d04..23f5c9898 100644
--- a/src/nix/command.hh
+++ b/src/nix/command.hh
@@ -1,5 +1,6 @@
#pragma once
+#include "installables.hh"
#include "args.hh"
#include "common-eval-args.hh"
#include "path.hh"
@@ -22,34 +23,7 @@ private:
std::shared_ptr<Store> _store;
};
-struct Buildable
-{
- std::optional<StorePath> drvPath;
- std::map<std::string, StorePath> outputs;
-};
-
-typedef std::vector<Buildable> Buildables;
-
-struct Installable
-{
- virtual ~Installable() { }
-
- virtual std::string what() = 0;
-
- virtual Buildables toBuildables()
- {
- throw Error("argument '%s' cannot be built", what());
- }
-
- Buildable toBuildable();
-
- virtual std::pair<Value *, Pos> toValue(EvalState & state)
- {
- throw Error("argument '%s' cannot be evaluated", what());
- }
-};
-
-struct SourceExprCommand : virtual Args, StoreCommand, MixEvalArgs
+struct SourceExprCommand : virtual StoreCommand, MixEvalArgs
{
Path file;
@@ -184,4 +158,36 @@ std::set<StorePath> toDerivations(ref<Store> store,
filename:lineno. */
Strings editorFor(const Pos & pos);
+struct MixProfile : virtual StoreCommand
+{
+ std::optional<Path> profile;
+
+ MixProfile();
+
+ /* If 'profile' is set, make it point at 'storePath'. */
+ void updateProfile(const StorePath & storePath);
+
+ /* If 'profile' is set, make it point at the store path produced
+ by 'buildables'. */
+ void updateProfile(const Buildables & buildables);
+};
+
+struct MixDefaultProfile : MixProfile
+{
+ MixDefaultProfile();
+};
+
+struct MixEnvironment : virtual Args {
+
+ StringSet keep, unset;
+ Strings stringsEnv;
+ std::vector<char*> vectorEnv;
+ bool ignoreEnvironment;
+
+ MixEnvironment();
+
+ /* Modify global environ based on ignoreEnvironment, keep, and unset. It's expected that exec will be called before this class goes out of scope, otherwise environ will become invalid. */
+ void setEnviron();
+};
+
}
diff --git a/src/nix/installables.cc b/src/nix/installables.cc
index 013218cd9..f464d0aa1 100644
--- a/src/nix/installables.cc
+++ b/src/nix/installables.cc
@@ -109,6 +109,11 @@ struct InstallableStorePath : Installable
bs.push_back(std::move(b));
return bs;
}
+
+ std::optional<StorePath> getStorePath() override
+ {
+ return storePath.clone();
+ }
};
struct InstallableValue : Installable
diff --git a/src/nix/installables.hh b/src/nix/installables.hh
new file mode 100644
index 000000000..503984220
--- /dev/null
+++ b/src/nix/installables.hh
@@ -0,0 +1,45 @@
+#pragma once
+
+#include "util.hh"
+#include "path.hh"
+#include "eval.hh"
+
+#include <optional>
+
+namespace nix {
+
+struct Buildable
+{
+ std::optional<StorePath> drvPath;
+ std::map<std::string, StorePath> outputs;
+};
+
+typedef std::vector<Buildable> Buildables;
+
+struct Installable
+{
+ virtual ~Installable() { }
+
+ virtual std::string what() = 0;
+
+ virtual Buildables toBuildables()
+ {
+ throw Error("argument '%s' cannot be built", what());
+ }
+
+ Buildable toBuildable();
+
+ virtual std::pair<Value *, Pos> toValue(EvalState & state)
+ {
+ throw Error("argument '%s' cannot be evaluated", what());
+ }
+
+ /* Return a value only if this installable is a store path or a
+ symlink to it. */
+ virtual std::optional<StorePath> getStorePath()
+ {
+ return {};
+ }
+};
+
+}
diff --git a/src/nix/run.cc b/src/nix/run.cc
index f885c5e49..8e30264c0 100644
--- a/src/nix/run.cc
+++ b/src/nix/run.cc
@@ -8,6 +8,7 @@
#include "fs-accessor.hh"
#include "progress-bar.hh"
#include "affinity.hh"
+#include "eval.hh"
#if __linux__
#include <sys/mount.h>
@@ -19,11 +20,46 @@ using namespace nix;
std::string chrootHelperName = "__run_in_chroot";
-struct CmdRun : InstallablesCommand
+struct RunCommon : virtual Command
+{
+ void runProgram(ref<Store> store,
+ const std::string & program,
+ const Strings & args)
+ {
+ stopProgressBar();
+
+ restoreSignals();
+
+ restoreAffinity();
+
+ /* If this is a diverted store (i.e. its "logical" location
+ (typically /nix/store) differs from its "physical" location
+ (e.g. /home/eelco/nix/store), then run the command in a
+ chroot. For non-root users, this requires running it in new
+ mount and user namespaces. Unfortunately,
+ unshare(CLONE_NEWUSER) doesn't work in a multithreaded
+ program (which "nix" is), so we exec() a single-threaded
+ helper program (chrootHelper() below) to do the work. */
+ auto store2 = store.dynamic_pointer_cast<LocalStore>();
+
+ if (store2 && store->storeDir != store2->realStoreDir) {
+ Strings helperArgs = { chrootHelperName, store->storeDir, store2->realStoreDir, program };
+ for (auto & arg : args) helperArgs.push_back(arg);
+
+ execv(readLink("/proc/self/exe").c_str(), stringsToCharPtrs(helperArgs).data());
+
+ throw SysError("could not execute chroot helper");
+ }
+
+ execvp(program.c_str(), stringsToCharPtrs(args).data());
+
+ throw SysError("unable to execute '%s'", program);
+ }
+};
+
+struct CmdRun : InstallablesCommand, RunCommon, MixEnvironment
{
std::vector<std::string> command = { "bash" };
- StringSet keep, unset;
- bool ignoreEnvironment = false;
CmdRun()
{
@@ -37,28 +73,6 @@ struct CmdRun : InstallablesCommand
if (ss.empty()) throw UsageError("--command requires at least one argument");
command = ss;
});
-
- mkFlag()
- .longName("ignore-environment")
- .shortName('i')
- .description("clear the entire environment (except those specified with --keep)")
- .set(&ignoreEnvironment, true);
-
- mkFlag()
- .longName("keep")
- .shortName('k')
- .description("keep specified environment variable")
- .arity(1)
- .labels({"name"})
- .handler([&](std::vector<std::string> ss) { keep.insert(ss.front()); });
-
- mkFlag()
- .longName("unset")
- .shortName('u')
- .description("unset specified environment variable")
- .arity(1)
- .labels({"name"})
- .handler([&](std::vector<std::string> ss) { unset.insert(ss.front()); });
}
std::string description() override
@@ -94,35 +108,13 @@ struct CmdRun : InstallablesCommand
auto accessor = store->getFSAccessor();
- if (ignoreEnvironment) {
-
- if (!unset.empty())
- throw UsageError("--unset does not make sense with --ignore-environment");
-
- std::map<std::string, std::string> kept;
- for (auto & var : keep) {
- auto s = getenv(var.c_str());
- if (s) kept[var] = s;
- }
-
- clearEnv();
-
- for (auto & var : kept)
- setenv(var.first.c_str(), var.second.c_str(), 1);
-
- } else {
-
- if (!keep.empty())
- throw UsageError("--keep does not make sense without --ignore-environment");
-
- for (auto & var : unset)
- unsetenv(var.c_str());
- }
std::unordered_set<StorePath> done;
std::queue<StorePath> todo;
for (auto & path : outPaths) todo.push(path.clone());
+ setEnviron();
+
auto unixPath = tokenizeString<Strings>(getEnv("PATH").value_or(""), ":");
while (!todo.empty()) {
@@ -142,38 +134,10 @@ struct CmdRun : InstallablesCommand
setenv("PATH", concatStringsSep(":", unixPath).c_str(), 1);
- std::string cmd = *command.begin();
Strings args;
for (auto & arg : command) args.push_back(arg);
- stopProgressBar();
-
- restoreSignals();
-
- restoreAffinity();
-
- /* If this is a diverted store (i.e. its "logical" location
- (typically /nix/store) differs from its "physical" location
- (e.g. /home/eelco/nix/store), then run the command in a
- chroot. For non-root users, this requires running it in new
- mount and user namespaces. Unfortunately,
- unshare(CLONE_NEWUSER) doesn't work in a multithreaded
- program (which "nix" is), so we exec() a single-threaded
- helper program (chrootHelper() below) to do the work. */
- auto store2 = store.dynamic_pointer_cast<LocalStore>();
-
- if (store2 && store->storeDir != store2->realStoreDir) {
- Strings helperArgs = { chrootHelperName, store->storeDir, store2->realStoreDir, cmd };
- for (auto & arg : args) helperArgs.push_back(arg);
-
- execv(readLink("/proc/self/exe").c_str(), stringsToCharPtrs(helperArgs).data());
-
- throw SysError("could not execute chroot helper");
- }
-
- execvp(cmd.c_str(), stringsToCharPtrs(args).data());
-
- throw SysError("unable to exec '%s'", cmd);
+ runProgram(store, *command.begin(), args);
}
};
diff --git a/src/nix/shell.cc b/src/nix/shell.cc
new file mode 100644
index 000000000..82b1da552
--- /dev/null
+++ b/src/nix/shell.cc
@@ -0,0 +1,319 @@
+#include "eval.hh"
+#include "command.hh"
+#include "common-args.hh"
+#include "shared.hh"
+#include "store-api.hh"
+#include "derivations.hh"
+#include "affinity.hh"
+#include "progress-bar.hh"
+
+#include <regex>
+
+using namespace nix;
+
+struct Var
+{
+ bool exported;
+ std::string value; // quoted string or array
+};
+
+struct BuildEnvironment
+{
+ std::map<std::string, Var> env;
+ std::string bashFunctions;
+};
+
+BuildEnvironment readEnvironment(const Path & path)
+{
+ BuildEnvironment res;
+
+ std::set<std::string> exported;
+
+ debug("reading environment file '%s'", path);
+
+ auto file = readFile(path);
+
+ auto pos = file.cbegin();
+
+ static std::string varNameRegex =
+ R"re((?:[a-zA-Z_][a-zA-Z0-9_]*))re";
+
+ static std::regex declareRegex(
+ "^declare -x (" + varNameRegex + ")" +
+ R"re((?:="((?:[^"\\]|\\.)*)")?\n)re");
+
+ static std::string simpleStringRegex =
+ R"re((?:[a-zA-Z0-9_/:\.\-\+=]*))re";
+
+ static std::string quotedStringRegex =
+ R"re((?:\$?'(?:[^'\\]|\\[abeEfnrtv\\'"?])*'))re";
+
+ static std::string arrayRegex =
+ R"re((?:\(( *\[[^\]]+\]="(?:[^"\\]|\\.)*")*\)))re";
+
+ static std::regex varRegex(
+ "^(" + varNameRegex + ")=(" + simpleStringRegex + "|" + quotedStringRegex + "|" + arrayRegex + ")\n");
+
+ static std::regex functionRegex(
+ "^" + varNameRegex + " \\(\\) *\n");
+
+ while (pos != file.end()) {
+
+ std::smatch match;
+
+ if (std::regex_search(pos, file.cend(), match, declareRegex)) {
+ pos = match[0].second;
+ exported.insert(match[1]);
+ }
+
+ else if (std::regex_search(pos, file.cend(), match, varRegex)) {
+ pos = match[0].second;
+ res.env.insert({match[1], Var { (bool) exported.count(match[1]), match[2] }});
+ }
+
+ else if (std::regex_search(pos, file.cend(), match, functionRegex)) {
+ res.bashFunctions = std::string(pos, file.cend());
+ break;
+ }
+
+ else throw Error("shell environment '%s' has unexpected line '%s'",
+ path, file.substr(pos - file.cbegin(), 60));
+ }
+
+ return res;
+}
+
+/* Given an existing derivation, return the shell environment as
+ initialised by stdenv's setup script. We do this by building a
+ modified derivation with the same dependencies and nearly the same
+ initial environment variables, that just writes the resulting
+ environment to a file and exits. */
+StorePath getDerivationEnvironment(ref<Store> store, Derivation drv)
+{
+ auto builder = baseNameOf(drv.builder);
+ if (builder != "bash")
+ throw Error("'nix shell' only works on derivations that use 'bash' as their builder");
+
+ drv.args = {
+ "-c",
+ "set -e; "
+ "export IN_NIX_SHELL=impure; "
+ "export dontAddDisableDepTrack=1; "
+ "if [[ -n $stdenv ]]; then "
+ " source $stdenv/setup; "
+ "fi; "
+ "export > $out; "
+ "set >> $out "};
+
+ /* Remove derivation checks. */
+ drv.env.erase("allowedReferences");
+ drv.env.erase("allowedRequisites");
+ drv.env.erase("disallowedReferences");
+ drv.env.erase("disallowedRequisites");
+
+ // FIXME: handle structured attrs
+
+ /* Rehash and write the derivation. FIXME: would be nice to use
+ 'buildDerivation', but that's privileged. */
+ auto drvName = drv.env["name"] + "-env";
+ for (auto & output : drv.outputs)
+ drv.env.erase(output.first);
+ drv.env["out"] = "";
+ drv.env["outputs"] = "out";
+ Hash h = hashDerivationModulo(*store, drv, true);
+ auto shellOutPath = store->makeOutputPath("out", h, drvName);
+ drv.outputs.insert_or_assign("out", DerivationOutput(shellOutPath.clone(), "", ""));
+ drv.env["out"] = store->printStorePath(shellOutPath);
+ auto shellDrvPath2 = writeDerivation(store, drv, drvName);
+
+ /* Build the derivation. */
+ store->buildPaths({shellDrvPath2});
+
+ assert(store->isValidPath(shellOutPath));
+
+ return shellOutPath;
+}
+
+struct Common : InstallableCommand, MixProfile
+{
+ std::set<string> ignoreVars{
+ "BASHOPTS",
+ "EUID",
+ "HOME", // FIXME: don't ignore in pure mode?
+ "NIX_BUILD_TOP",
+ "NIX_ENFORCE_PURITY",
+ "NIX_LOG_FD",
+ "PPID",
+ "PWD",
+ "SHELLOPTS",
+ "SHLVL",
+ "SSL_CERT_FILE", // FIXME: only want to ignore /no-cert-file.crt
+ "TEMP",
+ "TEMPDIR",
+ "TERM",
+ "TMP",
+ "TMPDIR",
+ "TZ",
+ "UID",
+ };
+
+ void makeRcScript(const BuildEnvironment & buildEnvironment, std::ostream & out)
+ {
+ out << "nix_saved_PATH=\"$PATH\"\n";
+
+ for (auto & i : buildEnvironment.env) {
+ if (!ignoreVars.count(i.first) && !hasPrefix(i.first, "BASH_")) {
+ out << fmt("%s=%s\n", i.first, i.second.value);
+ if (i.second.exported)
+ out << fmt("export %s\n", i.first);
+ }
+ }
+
+ out << "PATH=\"$PATH:$nix_saved_PATH\"\n";
+
+ out << buildEnvironment.bashFunctions << "\n";
+
+ // FIXME: set outputs
+
+ out << "export NIX_BUILD_TOP=\"$(mktemp -d --tmpdir nix-shell.XXXXXX)\"\n";
+ for (auto & i : {"TMP", "TMPDIR", "TEMP", "TEMPDIR"})
+ out << fmt("export %s=\"$NIX_BUILD_TOP\"\n", i);
+
+ out << "eval \"$shellHook\"\n";
+ }
+
+ StorePath getShellOutPath(ref<Store> store)
+ {
+ auto path = installable->getStorePath();
+ if (path && hasSuffix(path->to_string(), "-env"))
+ return path->clone();
+ else {
+ auto drvs = toDerivations(store, {installable});
+
+ if (drvs.size() != 1)
+ throw Error("'%s' needs to evaluate to a single derivation, but it evaluated to %d derivations",
+ installable->what(), drvs.size());
+
+ auto & drvPath = *drvs.begin();
+
+ return getDerivationEnvironment(store, store->derivationFromPath(drvPath));
+ }
+ }
+
+ BuildEnvironment getBuildEnvironment(ref<Store> store)
+ {
+ auto shellOutPath = getShellOutPath(store);
+
+ updateProfile(shellOutPath);
+
+ return readEnvironment(store->printStorePath(shellOutPath));
+ }
+};
+
+struct CmdDevShell : Common, MixEnvironment
+{
+ std::vector<std::string> command;
+
+ CmdDevShell()
+ {
+ mkFlag()
+ .longName("command")
+ .shortName('c')
+ .description("command and arguments to be executed insted of an interactive shell")
+ .labels({"command", "args"})
+ .arity(ArityAny)
+ .handler([&](std::vector<std::string> ss) {
+ if (ss.empty()) throw UsageError("--command requires at least one argument");
+ command = ss;
+ });
+ }
+
+ std::string description() override
+ {
+ return "run a bash shell that provides the build environment of a derivation";
+ }
+
+ Examples examples() override
+ {
+ return {
+ Example{
+ "To get the build environment of GNU hello:",
+ "nix dev-shell nixpkgs.hello"
+ },
+ Example{
+ "To store the build environment in a profile:",
+ "nix dev-shell --profile /tmp/my-shell nixpkgs.hello"
+ },
+ Example{
+ "To use a build environment previously recorded in a profile:",
+ "nix dev-shell /tmp/my-shell"
+ },
+ };
+ }
+
+ void run(ref<Store> store) override
+ {
+ auto buildEnvironment = getBuildEnvironment(store);
+
+ auto [rcFileFd, rcFilePath] = createTempFile("nix-shell");
+
+ std::ostringstream ss;
+ makeRcScript(buildEnvironment, ss);
+
+ ss << fmt("rm -f '%s'\n", rcFilePath);
+
+ if (!command.empty()) {
+ std::vector<std::string> args;
+ for (auto s : command)
+ args.push_back(shellEscape(s));
+ ss << fmt("exec %s\n", concatStringsSep(" ", args));
+ }
+
+ writeFull(rcFileFd.get(), ss.str());
+
+ stopProgressBar();
+
+ auto shell = getEnv("SHELL").value_or("bash");
+
+ setEnviron();
+
+ auto args = Strings{std::string(baseNameOf(shell)), "--rcfile", rcFilePath};
+
+ restoreAffinity();
+ restoreSignals();
+
+ execvp(shell.c_str(), stringsToCharPtrs(args).data());
+
+ throw SysError("executing shell '%s'", shell);
+ }
+};
+
+struct CmdPrintDevEnv : Common
+{
+ std::string description() override
+ {
+ return "print shell code that can be sourced by bash to reproduce the build environment of a derivation";
+ }
+
+ Examples examples() override
+ {
+ return {
+ Example{
+ "To apply the build environment of GNU hello to the current shell:",
+ ". <(nix print-dev-env nixpkgs.hello)"
+ },
+ };
+ }
+
+ void run(ref<Store> store) override
+ {
+ auto buildEnvironment = getBuildEnvironment(store);
+
+ stopProgressBar();
+
+ makeRcScript(buildEnvironment, std::cout);
+ }
+};
+
+static auto r1 = registerCommand<CmdPrintDevEnv>("print-dev-env");
+static auto r2 = registerCommand<CmdDevShell>("dev-shell");