feat: add try-catch to some usages of readLine

src/libmain/progress-bar.cc

@@ -558,7 +558,14 @@ std::optional<char> ProgressBar::ask(std::string_view msg)
     auto state(state_.lock());
     if (state->paused > 0 || !isatty(STDIN_FILENO)) return {};
     std::cerr << fmt("\r\e[K%s ", msg);
-    auto s = trim(readLine(STDIN_FILENO));
+    auto s = [&]() {
+        try {
+            return trim(readLine(STDIN_FILENO));
+        } catch (Error & e) {
+            e.addTrace({}, "while trying to read from STDIN to ask something");
+            throw;
+        }
+    }();
     if (s.size() != 1) return {};
     draw(*state, {});
     return s[0];

src/libstore/platform/linux.cc

@@ -930,7 +930,14 @@ Pid LinuxLocalDerivationGoal::startChild(std::function<void()> openSlave)
         userNamespaceSync.writeSide.reset();
     });
 
-    auto ss = tokenizeString<std::vector<std::string>>(readLine(sendPid.readSide.get()));
+    auto ss = [&]() {
+        try {
+            return tokenizeString<std::vector<std::string>>(readLine(sendPid.readSide.get()));
+        } catch (Error & e) {
+            e.addTrace({}, "while... how am I supposed to know?");
+            throw;
+        }
+    }();
     assert(ss.size() == 1);
     Pid pid = Pid{string2Int<pid_t>(ss[0]).value()};