diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 93d8a53a..764fa90b 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -57,8 +57,6 @@ jobs:
             -D CMAKE_INSTALL_LIBDIR=lib \
             -D PYTHON_EXECUTABLE=`which python` \
             -D XPYT_BUILD_TESTS=ON \
-            -D CMAKE_C_COMPILER=$CC \
-            -D CMAKE_CXX_COMPILER=$CXX \
             ${{ env.CMAKE_EXTRA_ARGS }}
         working-directory: build
 
diff --git a/environment-dev.yml b/environment-dev.yml
index eb273d25..f3925418 100644
--- a/environment-dev.yml
+++ b/environment-dev.yml
@@ -16,7 +16,7 @@ dependencies:
   # of a spurious bug in debugpy
   - python <3.13
   - pip
-  - xeus-python-shell>=0.7.0,<0.8
+  - xeus-python-shell>=0.8.0,<0.9
   - debugpy>=1.6.5
   - ipython
   # Test dependencies
diff --git a/environment-wasm-host.yml b/environment-wasm-host.yml
index afdc4e0f..efd13000 100644
--- a/environment-wasm-host.yml
+++ b/environment-wasm-host.yml
@@ -15,7 +15,7 @@ dependencies:
   - pyjs >=4,<5
   - libpython
   - zstd
-  - openssl
+  - openssl <4
   - xz
   - ipywidgets
   - xeus-python-shell>=0.7.0,<0.8
diff --git a/src/xdebugger.cpp b/src/xdebugger.cpp
index 9bbe8f1c..c123eb3a 100644
--- a/src/xdebugger.cpp
+++ b/src/xdebugger.cpp
@@ -212,9 +212,30 @@ namespace xpyt
 
         std::string src_var_name = message["arguments"]["srcVariableName"].get<std::string>();
         std::string dst_var_name = message["arguments"]["dstVariableName"].get<std::string>();
-        int src_frame_id = message["arguments"]["srcFrameId"].get<int>();
+        bool valid = false;
+        {
+            py::gil_scoped_acquire acquire;
+            py::str py_src_var_name = py::str(src_var_name);
+            py::str py_dst_var_name = py::str(dst_var_name);
+            bool valid_src_name = PyUnicode_IsIdentifier(py_src_var_name.ptr()) == 1;
+            bool valid_dst_name = PyUnicode_IsIdentifier(py_dst_var_name.ptr()) == 1;
+            valid = valid_src_name && valid_dst_name;
+        }
+
+        if (!valid)
+        {
+            nl::json reply = {
+                {"type", "response"},
+                {"request_seq", message["seq"]},
+                {"success", false},
+                {"command", message["command"]},
+                {"message", "dstVariableName and srcVariableName must be valid identifiers"}
+            };
+            return reply;
+        }
 
         // It basically runs a setExpression in the globals dictionary of Python.
+        int src_frame_id = message["arguments"]["srcFrameId"].get<int>();
         int seq = message["seq"].get<int>();
         std::string expression = "globals()['" + dst_var_name + "']";
         nl::json request = {