diff --git a/src/libexpr/c/nix_api_value.cc b/src/libexpr/c/nix_api_value.cc
index e63d13f7a..740751beb 100644
--- a/src/libexpr/c/nix_api_value.cc
+++ b/src/libexpr/c/nix_api_value.cc
@@ -382,13 +382,13 @@ nix_err nix_init_string(nix_c_context * context, Value * value, const char * str
     NIXC_CATCH_ERRS
 }
 
-nix_err nix_init_path_string(nix_c_context * context, Value * value, const char * str)
+nix_err nix_init_path_string(nix_c_context * context, EvalState * s, Value * value, const char * str)
 {
     if (context)
         context->last_err_code = NIX_OK;
     try {
         auto & v = check_value_not_null(value);
-        v.mkPath(std::string_view(str));
+        v.mkPath(s->state.rootPath(nix::CanonPath(str)));
     }
     NIXC_CATCH_ERRS
 }
diff --git a/src/libexpr/c/nix_api_value.h b/src/libexpr/c/nix_api_value.h
index 64c0c367a..e3e937e37 100644
--- a/src/libexpr/c/nix_api_value.h
+++ b/src/libexpr/c/nix_api_value.h
@@ -129,6 +129,7 @@ nix_err nix_register_primop(nix_c_context * context, PrimOp * primOp);
  * @return value, or null in case of errors
  *
  */
+
 Value * nix_alloc_value(nix_c_context * context, EvalState * state);
 /** @addtogroup value_manip Manipulating values
  * @brief Functions to inspect and change Nix language values, represented by Value.
@@ -142,6 +143,7 @@ Value * nix_alloc_value(nix_c_context * context, EvalState * state);
  * @param[in] value Nix value to inspect
  * @return type of nix value
  */
+
 ValueType nix_get_type(nix_c_context * context, const Value * value);
 /** @brief Get type name of value as defined in the evaluator
  * @param[out] context Optional, stores error information
@@ -149,6 +151,7 @@ ValueType nix_get_type(nix_c_context * context, const Value * value);
  * @return type name, owned string
  * @todo way to free the result
  */
+
 const char * nix_get_typename(nix_c_context * context, const Value * value);
 
 /** @brief Get boolean value
@@ -290,24 +293,24 @@ nix_err nix_init_bool(nix_c_context * context, Value * value, bool b);
  * @param[in] str the string, copied
  * @return error code, NIX_OK on success.
  */
-
 nix_err nix_init_string(nix_c_context * context, Value * value, const char * str);
+
 /** @brief Set a path
  * @param[out] context Optional, stores error information
  * @param[out] value Nix value to modify
  * @param[in] str the path string, copied
  * @return error code, NIX_OK on success.
  */
+nix_err nix_init_path_string(nix_c_context * context, EvalState * s, Value * value, const char * str);
 
-nix_err nix_init_path_string(nix_c_context * context, Value * value, const char * str);
 /** @brief Set a float
  * @param[out] context Optional, stores error information
  * @param[out] value Nix value to modify
  * @param[in] d the float, 64-bits
  * @return error code, NIX_OK on success.
  */
-
 nix_err nix_init_float(nix_c_context * context, Value * value, double d);
+
 /** @brief Set an int
  * @param[out] context Optional, stores error information
  * @param[out] value Nix value to modify
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index a93e531b6..794451d82 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -897,11 +897,6 @@ void Value::mkStringMove(const char * s, const NixStringContext & context)
     copyContextToValue(*this, context);
 }
 
-void Value::mkPath(std::string_view path)
-{
-    mkPath(makeImmutableString(path));
-}
-
 void Value::mkPath(const SourcePath & path)
 {
     mkPath(&*path.accessor, makeImmutableString(path.path.abs()));
diff --git a/tests/unit/libexpr/nix_api_external.cc b/tests/unit/libexpr/nix_api_external.cc
index 1f190d9c8..68766fd47 100644
--- a/tests/unit/libexpr/nix_api_external.cc
+++ b/tests/unit/libexpr/nix_api_external.cc
@@ -31,7 +31,6 @@ private:
 
     static void type_of_function(void * self, nix_string_return * res)
     {
-        std::cout << self << std::endl;
         MyExternalValueDesc * obj = static_cast<MyExternalValueDesc *>(self);
 
         std::string type_string = "nix-external<MyExternalValueDesc( ";
diff --git a/tests/unit/libexpr/nix_api_value.cc b/tests/unit/libexpr/nix_api_value.cc
index abed456f7..2f98297b3 100644
--- a/tests/unit/libexpr/nix_api_value.cc
+++ b/tests/unit/libexpr/nix_api_value.cc
@@ -18,6 +18,56 @@ TEST_F(nix_api_expr_test, nix_value_set_get_int)
     nix_init_int(nullptr, value, myInt);
 
     ASSERT_EQ(myInt, nix_get_int(nullptr, value));
+    ASSERT_STREQ("an integer", nix_get_typename(nullptr, value));
+    ASSERT_EQ(NIX_TYPE_INT, nix_get_type(nullptr, value));
+}
+
+TEST_F(nix_api_expr_test, nix_value_set_get_float)
+{
+    float myDouble = 1.0;
+    nix_init_float(nullptr, value, myDouble);
+
+    ASSERT_EQ(myDouble, nix_get_float(nullptr, value));
+    ASSERT_STREQ("a float", nix_get_typename(nullptr, value));
+    ASSERT_EQ(NIX_TYPE_FLOAT, nix_get_type(nullptr, value));
+}
+
+TEST_F(nix_api_expr_test, nix_value_set_get_bool)
+{
+    bool myBool = true;
+    nix_init_bool(nullptr, value, myBool);
+
+    ASSERT_EQ(myBool, nix_get_bool(nullptr, value));
+    ASSERT_STREQ("a Boolean", nix_get_typename(nullptr, value));
+    ASSERT_EQ(NIX_TYPE_BOOL, nix_get_type(nullptr, value));
+}
+
+TEST_F(nix_api_expr_test, nix_value_set_get_string)
+{
+    const char * myString = "some string";
+    nix_init_string(nullptr, value, myString);
+
+    ASSERT_STREQ(myString, nix_get_string(nullptr, value));
+    ASSERT_STREQ("a string", nix_get_typename(nullptr, value));
+    ASSERT_EQ(NIX_TYPE_STRING, nix_get_type(nullptr, value));
+}
+
+TEST_F(nix_api_expr_test, nix_value_set_get_null)
+{
+    nix_init_null(nullptr, value);
+
+    ASSERT_STREQ("null", nix_get_typename(nullptr, value));
+    ASSERT_EQ(NIX_TYPE_NULL, nix_get_type(nullptr, value));
+}
+
+TEST_F(nix_api_expr_test, nix_value_set_get_path)
+{
+    const char * p = "/nix/store/40s0qmrfb45vlh6610rk29ym318dswdr-myname";
+    nix_init_path_string(nullptr, state, value, p);
+
+    ASSERT_STREQ(p, nix_get_path_string(nullptr, value));
+    ASSERT_STREQ("a path", nix_get_typename(nullptr, value));
+    ASSERT_EQ(NIX_TYPE_PATH, nix_get_type(nullptr, value));
 }
 
 TEST_F(nix_api_expr_test, nix_build_and_init_list)
@@ -34,6 +84,9 @@ TEST_F(nix_api_expr_test, nix_build_and_init_list)
     ASSERT_EQ(42, nix_get_int(nullptr, nix_get_list_byidx(nullptr, value, state, 0)));
     ASSERT_EQ(1, nix_get_list_size(nullptr, value));
 
+    ASSERT_STREQ("a list", nix_get_typename(nullptr, value));
+    ASSERT_EQ(NIX_TYPE_LIST, nix_get_type(nullptr, value));
+
     // Clean up
     nix_gc_decref(nullptr, intValue);
 }
@@ -80,6 +133,9 @@ TEST_F(nix_api_expr_test, nix_build_and_init_attr)
 
     ASSERT_STREQ("b", nix_get_attr_name_byidx(nullptr, value, state, 1));
 
+    ASSERT_STREQ("a set", nix_get_typename(nullptr, value));
+    ASSERT_EQ(NIX_TYPE_ATTRS, nix_get_type(nullptr, value));
+
     // Clean up
     nix_gc_decref(nullptr, intValue);
     nix_gc_decref(nullptr, stringValue);
diff --git a/tests/unit/libutil/nix_api_util.cc b/tests/unit/libutil/nix_api_util.cc
index 8cc2b6616..a3ec5e0a1 100644
--- a/tests/unit/libutil/nix_api_util.cc
+++ b/tests/unit/libutil/nix_api_util.cc
@@ -9,11 +9,12 @@
 
 namespace nixC {
 
-TEST_F(nix_api_util_context, nix_context_error) {
+TEST_F(nix_api_util_context, nix_context_error)
+{
     std::string err_msg_ref;
     try {
         throw nix::Error("testing error");
-    } catch(nix::Error &e) {
+    } catch (nix::Error & e) {
         err_msg_ref = e.what();
         nix_context_error(ctx);
     }
@@ -24,7 +25,7 @@ TEST_F(nix_api_util_context, nix_context_error) {
 
     try {
         throw std::runtime_error("testing exception");
-    } catch(std::exception &e) {
+    } catch (std::exception & e) {
         err_msg_ref = e.what();
         nix_context_error(ctx);
     }
@@ -32,14 +33,16 @@ TEST_F(nix_api_util_context, nix_context_error) {
     ASSERT_EQ(*ctx->last_err, err_msg_ref);
 }
 
-TEST_F(nix_api_util_context, nix_set_err_msg) {
+TEST_F(nix_api_util_context, nix_set_err_msg)
+{
     ASSERT_EQ(ctx->last_err_code, NIX_OK);
     nix_set_err_msg(ctx, NIX_ERR_UNKNOWN, "unknown test error");
     ASSERT_EQ(ctx->last_err_code, NIX_ERR_UNKNOWN);
     ASSERT_EQ(*ctx->last_err, "unknown test error");
 }
 
-TEST(nix_api_util, nix_version_get) {
+TEST(nix_api_util, nix_version_get)
+{
     ASSERT_EQ(std::string(nix_version_get()), PACKAGE_VERSION);
 }
 
@@ -77,9 +80,10 @@ TEST_F(nix_api_util_context, nix_setting_set)
     ASSERT_STREQ("new-value", value);
 }
 
-TEST_F(nix_api_util_context, nix_err_msg) {
+TEST_F(nix_api_util_context, nix_err_msg)
+{
     // no error
-    EXPECT_THROW(nix_err_msg(NULL, ctx, NULL), nix::Error);
+    EXPECT_THROW(nix_err_msg(nullptr, ctx, NULL), nix::Error);
 
     // set error
     nix_set_err_msg(ctx, NIX_ERR_UNKNOWN, "unknown test error");
@@ -90,46 +94,49 @@ TEST_F(nix_api_util_context, nix_err_msg) {
 
     // advanced usage
     unsigned int sz;
-    err_msg = nix_err_msg(NULL, ctx, &sz);
+    err_msg = nix_err_msg(nix_c_context_create(), ctx, &sz);
     ASSERT_EQ(sz, err_msg.size());
 }
 
-TEST_F(nix_api_util_context, nix_err_info_msg) {
+TEST_F(nix_api_util_context, nix_err_info_msg)
+{
     // no error
     EXPECT_THROW(nix_err_info_msg(NULL, ctx, NULL, 256), nix::Error);
 
     try {
         throw nix::Error("testing error");
-    } catch(...) {
+    } catch (...) {
         nix_context_error(ctx);
     }
     char buf[256];
-    nix_err_info_msg(NULL, ctx, buf, 256);
+    nix_err_info_msg(nix_c_context_create(), ctx, buf, 256);
     ASSERT_EQ(std::string(buf), "testing error");
 
     // should overflow
     EXPECT_THROW(nix_err_info_msg(NULL, ctx, buf, 1), nix::Error);
 }
 
-TEST_F(nix_api_util_context, nix_err_name) {
+TEST_F(nix_api_util_context, nix_err_name)
+{
     // no error
     EXPECT_THROW(nix_err_name(NULL, ctx, NULL, 256), nix::Error);
 
     std::string err_msg_ref;
     try {
         throw nix::Error("testing error");
-    } catch(...) {
+    } catch (...) {
         nix_context_error(ctx);
     }
     char err_name[32];
-    nix_err_name(NULL, ctx, err_name, 32);
+    nix_err_name(nix_c_context_create(), ctx, err_name, 32);
     ASSERT_EQ(std::string(err_name), "nix::Error");
 
     // overflow
     EXPECT_THROW(nix_err_name(NULL, ctx, err_name, 1), nix::Error);
 }
 
-TEST_F(nix_api_util_context, nix_err_code) {
+TEST_F(nix_api_util_context, nix_err_code)
+{
     ASSERT_EQ(nix_err_code(ctx), NIX_OK);
     nix_set_err_msg(ctx, NIX_ERR_UNKNOWN, "unknown test error");
     ASSERT_EQ(nix_err_code(ctx), NIX_ERR_UNKNOWN);