diff --git a/.gitignore b/.gitignore
index d56edb0c..dba36282 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,6 +14,7 @@ testmaps/*.bsp
 testmaps/*.bsp.qbsplog
 testmaps/*.log
 testmaps/*.prt
+testmaps/*.lit
 testmaps/*.obj
 testmaps/*.pts
 testmaps/*.vis
diff --git a/include/common/mapfile.hh b/include/common/mapfile.hh
index d450125b..b68cd40f 100644
--- a/include/common/mapfile.hh
+++ b/include/common/mapfile.hh
@@ -79,7 +79,10 @@ struct texture_axis_t
     qvec3d snapped_normal;
 
     // use_new_axis = !qbsp_options.oldaxis.value()
-    constexpr texture_axis_t(const qplane3d &plane, bool use_new_axis = false)
+    constexpr texture_axis_t(const qplane3d &plane, bool use_new_axis = false) :
+        xv(), // gcc C++20 bug workaround
+        yv(),
+        snapped_normal()
     {
         constexpr qvec3d baseaxis[18] = {
             {0, 0, 1}, {1, 0, 0}, {0, -1, 0}, // floor
diff --git a/lightpreview/glview.cpp b/lightpreview/glview.cpp
index bc89f32b..d077070b 100644
--- a/lightpreview/glview.cpp
+++ b/lightpreview/glview.cpp
@@ -1397,7 +1397,7 @@ void GLView::renderBSP(const QString &file, const mbsp_t &bsp, const bspxentries
             double y = split[1].toDouble();
             double z = split[2].toDouble();
 
-            points.emplace_back(qvec3f{(float)x, (float)y, (float)z});
+            points.push_back(simple_vertex_t{qvec3f{(float)x, (float)y, (float)z}});
 
             num_leak_points++;
         }
@@ -1433,7 +1433,7 @@ void GLView::renderBSP(const QString &file, const mbsp_t &bsp, const bspxentries
 
             for (auto &pt : portal.winding) {
                 indices.push_back(current_index++);
-                points.emplace_back(pt);
+                points.push_back(simple_vertex_t{qvec3f{pt}});
             }
 
             indices.push_back((GLuint)-1);
diff --git a/lightpreview/mainwindow.cpp b/lightpreview/mainwindow.cpp
index f46e2aa2..548d1f90 100644
--- a/lightpreview/mainwindow.cpp
+++ b/lightpreview/mainwindow.cpp
@@ -709,16 +709,19 @@ int MainWindow::compileMap(const QString &file, bool is_reload)
             m_bspdata.loadversion->game->init_filesystem(file.toStdString(), settings);
         }
     } catch (const settings::parse_exception &p) {
+        // FIXME: threading error: don't call Qt widgets code from background thread
         auto *textEdit = m_outputLogWidget->textEdit(m_activeLogTab);
         textEdit->append(QString::fromUtf8(p.what()) + QString::fromLatin1("\n"));
         m_activeLogTab = ETLogTab::TAB_LIGHTPREVIEW;
         return 1;
     } catch (const settings::quit_after_help_exception &p) {
+        // FIXME: threading error: don't call Qt widgets code from background thread
         auto *textEdit = m_outputLogWidget->textEdit(m_activeLogTab);
         textEdit->append(QString::fromUtf8(p.what()) + QString::fromLatin1("\n"));
         m_activeLogTab = ETLogTab::TAB_LIGHTPREVIEW;
         return 1;
     } catch (const std::exception &other) {
+        // FIXME: threading error: don't call Qt widgets code from background thread
         auto *textEdit = m_outputLogWidget->textEdit(m_activeLogTab);
         textEdit->append(QString::fromUtf8(other.what()) + QString::fromLatin1("\n"));
         m_activeLogTab = ETLogTab::TAB_LIGHTPREVIEW;