Limit time to live for cache unavailability during ci command

include/vcpkg/binarycaching.h

@@ -3,6 +3,7 @@
 #include <vcpkg/fwd/dependencies.h>
 #include <vcpkg/fwd/vcpkgpaths.h>
 
+#include <vcpkg/base/chrono.h>
 #include <vcpkg/base/downloads.h>
 #include <vcpkg/base/expected.h>
 #include <vcpkg/base/files.h>
@@ -119,9 +120,18 @@ namespace vcpkg
         /// Returns a vector where each index corresponds to the matching index in `actions`.
         std::vector<CacheAvailability> precheck(const VcpkgPaths& paths, View<Dependencies::InstallPlanAction> actions);
 
+        /// Sets the time in seconds from now after which "unavailable" entries will be checked again.
+        /// A non-positive value disables re-checking.
+        void set_ttl_for_unavailable(int seconds);
+
     private:
+        /// Returns true when the lifetime for "unvailable" entries is exceeded.
+        bool must_recheck_unavailable_entries() const noexcept;
+
         std::unordered_map<std::string, CacheStatus> m_status;
         std::vector<std::unique_ptr<IBinaryProvider>> m_providers;
+        ElapsedTimer m_ttl_elapsed;
+        int m_ttl_for_unavailable = 0;
     };
 
     ExpectedS<Downloads::DownloadManagerConfig> parse_download_configuration(const Optional<std::string>& arg);

src/vcpkg/binarycaching.cpp

@@ -1146,6 +1146,20 @@ namespace vcpkg
         }
     }
 
+    void BinaryCache::set_ttl_for_unavailable(int seconds)
+    {
+        m_ttl_for_unavailable = seconds;
+        if (seconds > 0)
+        {
+            m_ttl_elapsed = ElapsedTimer::create_started();
+        }
+    }
+
+    bool BinaryCache::must_recheck_unavailable_entries() const noexcept
+    {
+        return m_ttl_for_unavailable > 0 && m_ttl_elapsed.elapsed().as<std::chrono::seconds>().count() > m_ttl_for_unavailable;
+    }
+
     RestoreResult BinaryCache::try_restore(const VcpkgPaths& paths, const Dependencies::InstallPlanAction& action)
     {
         const auto abi = action.package_abi().get();
@@ -1182,7 +1196,7 @@ namespace vcpkg
                 continue; // this one already tried :)
             }
 
-            if (cache_status.is_unavailable(m_providers.size()))
+            if (cache_status.is_unavailable(m_providers.size()) && !must_recheck_unavailable_entries())
             {
                 break;
             }

src/vcpkg/commands.ci.cpp

@@ -600,6 +600,7 @@ namespace vcpkg::Commands::CI
             StatusParagraphs status_db = database_load_check(paths);
 
             auto collection_timer = ElapsedTimer::create_started();
+            binary_cache.set_ttl_for_unavailable(120);
             auto summary = Install::perform(args,
                                             action_plan,
                                             Install::KeepGoing::YES,