1 files changed, 110 insertions, 0 deletions
diff --git a/src/nix/doctor.cc b/src/nix/doctor.cc
new file mode 100644
index 000000000000..b608b9d59efa
--- /dev/null
+++ b/src/nix/doctor.cc
@@ -0,0 +1,110 @@
+#include "command.hh"
+#include "serve-protocol.hh"
+#include "shared.hh"
+#include "store-api.hh"
+#include "worker-protocol.hh"
+
+using namespace nix;
+
+std::string formatProtocol(unsigned int proto)
+{
+    if (proto) {
+        auto major = GET_PROTOCOL_MAJOR(proto) >> 8;
+        auto minor = GET_PROTOCOL_MINOR(proto);
+        return (format("%1%.%2%") % major % minor).str();
+    }
+    return "unknown";
+}
+
+struct CmdDoctor : StoreCommand
+{
+    std::string name() override
+    {
+        return "doctor";
+    }
+
+    std::string description() override
+    {
+        return "check your system for potential problems";
+    }
+
+    void run(ref<Store> store) override
+    {
+        std::cout << "Store uri: " << store->getUri() << std::endl;
+        std::cout << std::endl;
+
+        auto type = getStoreType();
+
+        if (type < tOther) {
+            checkNixInPath();
+            checkProfileRoots(store);
+        }
+        checkStoreProtocol(store->getProtocol());
+    }
+
+    void checkNixInPath()
+    {
+        PathSet dirs;
+
+        for (auto & dir : tokenizeString<Strings>(getEnv("PATH"), ":"))
+            if (pathExists(dir + "/nix-env"))
+                dirs.insert(dirOf(canonPath(dir + "/nix-env", true)));
+
+        if (dirs.size() != 1) {
+            std::cout << "Warning: multiple versions of nix found in PATH." << std::endl;
+            std::cout << std::endl;
+            for (auto & dir : dirs)
+                std::cout << "  " << dir << std::endl;
+            std::cout << std::endl;
+        }
+    }
+
+    void checkProfileRoots(ref<Store> store)
+    {
+        PathSet dirs;
+
+        for (auto & dir : tokenizeString<Strings>(getEnv("PATH"), ":")) {
+            Path profileDir = dirOf(dir);
+            try {
+                Path userEnv = canonPath(profileDir, true);
+
+                if (store->isStorePath(userEnv) && hasSuffix(userEnv, "user-environment")) {
+                    while (profileDir.find("/profiles/") == std::string::npos && isLink(profileDir))
+                        profileDir = absPath(readLink(profileDir), dirOf(profileDir));
+
+                    if (profileDir.find("/profiles/") == std::string::npos)
+                        dirs.insert(dir);
+                }
+            } catch (SysError &) {}
+        }
+
+        if (!dirs.empty()) {
+            std::cout << "Warning: found profiles outside of " << settings.nixStateDir << "/profiles." << std::endl;
+            std::cout << "The generation this profile points to might not have a gcroot and could be" << std::endl;
+            std::cout << "garbage collected, resulting in broken symlinks." << std::endl;
+            std::cout << std::endl;
+            for (auto & dir : dirs)
+                std::cout << "  " << dir << std::endl;
+            std::cout << std::endl;
+        }
+    }
+
+    void checkStoreProtocol(unsigned int storeProto)
+    {
+        auto clientProto = GET_PROTOCOL_MAJOR(SERVE_PROTOCOL_VERSION) == GET_PROTOCOL_MAJOR(storeProto)
+            ? SERVE_PROTOCOL_VERSION
+            : PROTOCOL_VERSION;
+
+        if (clientProto != storeProto) {
+            std::cout << "Warning: protocol version of this client does not match the store." << std::endl;
+            std::cout << "While this is not necessarily a problem it's recommended to keep the client in" << std::endl;
+            std::cout << "sync with the daemon." << std::endl;
+            std::cout << std::endl;
+            std::cout << "Client protocol: " << formatProtocol(clientProto) << std::endl;
+            std::cout << "Store protocol: " << formatProtocol(storeProto) << std::endl;
+            std::cout << std::endl;
+        }
+    }
+};
+
+static RegisterCommand r1(make_ref<CmdDoctor>());