Get rid of most `.at` calls (#6393)

Use one of `get` or `getOr` instead which will either return a null-pointer (with a nicer error message) or a default value when the key is missing.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/libstore/build/worker.cc b/src/libstore/build/worker.cc
index f72c1cc9c..e7c01a737 100644
--- a/src/libstore/build/worker.cc
+++ b/src/libstore/build/worker.cc
@@ -380,7 +380,10 @@ void Worker::waitForInput()
         std::set<int> fds2(j->fds);
         std::vector<unsigned char> buffer(4096);
         for (auto & k : fds2) {
-            if (pollStatus.at(fdToPollStatus.at(k)).revents) {
+            const auto fdPollStatusId = get(fdToPollStatus, k);
+            assert(fdPollStatusId);
+            assert(*fdPollStatusId < pollStatus.size());
+            if (pollStatus.at(*fdPollStatusId).revents) {
                 ssize_t rd = ::read(k, buffer.data(), buffer.size());
                 // FIXME: is there a cleaner way to handle pt close
                 // than EIO? Is this even standard?