try to fix https://github.com/fsprojects/Paket/issues/2640

integrationtests/Paket.IntegrationTests/BasicResolverSpecs.fs

@@ -113,6 +113,7 @@ let ``#1189 should allow # in path``() =
     lockFile.Groups.[Constants.MainDependencyGroup].Resolution.[PackageName "FAKE"].Version
     |> shouldBeGreaterThan (SemVer.Parse "4.7.2")
 
+
 [<Test>]
 let ``#1247 shouldn't load lockfile in full update``() =
     updateEx true "i001247-lockfile-error" |> ignore
@@ -137,7 +138,10 @@ let ``#1450 should resolve with twiddle wakka``() =
     let lockFile = update "i001450-twiddle-wakka"
     lockFile.Groups.[Constants.MainDependencyGroup].Resolution.[PackageName "EnterpriseLibrary.SemanticLogging"].Version
     |> shouldBeSmallerThan (SemVer.Parse "3")
-
+
+[<Test>]
+let ``#2640 shouldn't try GetDetails if package only exists locally``() =
+    updateEx true "i002640" |> ignore
 
 #if INTERACTIVE
 ;;

integrationtests/scenarios/i002640/before/paket.dependencies

@@ -0,0 +1,4 @@
+source my-package-source
+source https://nuget.org/api/v2
+
+nuget paket-issue-i002640-never-exists-on-nuget-gallery 1.0.0

src/Paket.Core/Dependencies/NuGet.fs

@@ -15,6 +15,7 @@ open System.Runtime.ExceptionServices
 open System.Text
 open FSharp.Polyfill
 open Paket.NuGetCache
+open Paket.PackageResolver
 
 type NuGetContent =
     | NuGetDirectory of name:string * contents:NuGetContent list
@@ -233,7 +234,10 @@ let tryNuGetV3 (auth, nugetV3Url, package:PackageName) =
     NuGetV3.findVersionsForPackage(nugetV3Url, auth, package)
 
 
-let rec private getPackageDetails alternativeProjectRoot root force (sources:PackageSource list) packageName (version:SemVerInfo) : Async<PackageResolver.PackageDetails> =
+let rec private getPackageDetails alternativeProjectRoot root force (parameters:GetPackageDetailsParameters) : Async<PackageResolver.PackageDetails> =
+    let sources = parameters.Package.Sources
+    let packageName = parameters.Package.PackageName
+    let version = parameters.Version
     async {
         let inCache =
             sources
@@ -245,10 +249,12 @@ let rec private getPackageDetails alternativeProjectRoot root force (sources:Pac
         let tryV2 (nugetSource:NugetSource) force =
             NuGetV2.getDetailsFromNuGet
                 force
+                parameters.VersionIsAssumed
                 nugetSource
                 packageName
                 version
 
+
         let tryV3 (nugetSource:NugetV3Source) force =
             NuGetV3.GetPackageDetails force nugetSource packageName version
 
@@ -357,17 +363,17 @@ let rec private getPackageDetails alternativeProjectRoot root force (sources:Pac
               LicenseUrl = nugetObject.LicenseUrl
               DirectDependencies = NuGetPackageCache.getDependencies nugetObject |> Set.ofList } }
 
-let rec GetPackageDetails alternativeProjectRoot root force (sources:PackageSource list) groupName packageName (version:SemVerInfo) : Async<PackageResolver.PackageDetails> =
+let rec GetPackageDetails alternativeProjectRoot root force (parameters:GetPackageDetailsParameters): Async<PackageResolver.PackageDetails> =
     async {
         try
-            return! getPackageDetails alternativeProjectRoot root force sources packageName version
+            return! getPackageDetails alternativeProjectRoot root force parameters
         with
         | exn ->
             if verbose then
                 traceWarnfn "GetPackageDetails failed: %O" exn
             else
                 traceWarnfn "Something failed in GetPackageDetails, trying again with force: %s" exn.Message
-            return! getPackageDetails alternativeProjectRoot root true sources packageName version
+            return! getPackageDetails alternativeProjectRoot root true parameters
     }
 
 let protocolCache = System.Collections.Concurrent.ConcurrentDictionary<_,_>()
@@ -413,7 +419,9 @@ let getVersionsCached key f (source, auth, nugetURL, package) =
 
 
 /// Allows to retrieve all version no. for a package from the given sources.
-let GetVersions force alternativeProjectRoot root (sources, packageName:PackageName) = async {
+let GetVersions force alternativeProjectRoot root (parameters:GetPackageVersionsParameters) = async {
+    let packageName = parameters.Package.PackageName
+    let sources = parameters.Package.Sources
     let trial force = async {
         let getVersionsFailedCacheFileName (source:PackageSource) =
             let h = source.Url |> NuGetCache.normalizeUrl |> hash |> abs
@@ -671,7 +679,7 @@ let DownloadAndExtractPackage(alternativeProjectRoot, root, isLocalOverride:bool
                         let group = if groupName = Constants.MainDependencyGroup then "" else sprintf " (%O)" groupName
                         tracefn "Downloading %O %O%s" packageName version group
 
-                    let! nugetPackage = GetPackageDetails alternativeProjectRoot root force [source] groupName packageName version
+                    let! nugetPackage = GetPackageDetails alternativeProjectRoot root force (GetPackageDetailsParameters.ofParams [source] groupName packageName version)
 
                     let encodeURL (url:string) = url.Replace("+","%2B")
                     let downloadUri =

src/Paket.Core/Dependencies/NuGetCache.fs

@@ -465,12 +465,19 @@ let private tryUrlOrBlacklist (f: _ -> Async<'a>) (isOk : 'a -> bool) (source:Nu
     | FirstCall t ->
         FirstCall (t |> Task.Map (fun (l, r) -> l, (r :?> 'a)))
 
-let tryAndBlacklistUrl doWarn (source:NugetSource) (tryAgain : 'a -> bool) (f : string -> Async<'a>) (urls: UrlToTry list) : Async<'a>=
+let tryAndBlacklistUrl doBlackList doWarn (source:NugetSource) (tryAgain : 'a -> bool) (f : string -> Async<'a>) (urls: UrlToTry list) : Async<'a>=
     async {
         let! tasks, resultIndex =
             urls
             |> Seq.map (fun url -> async {
-                let cached = tryUrlOrBlacklist (fun () -> async { return! f url.InstanceUrl }) (tryAgain >> not) (source, url.UrlId)
+                let cached =
+                    if doBlackList then
+                        tryUrlOrBlacklist (fun () -> async { return! f url.InstanceUrl }) (tryAgain >> not) (source, url.UrlId)
+                    else 
+                        async {
+                            let! result = f url.InstanceUrl
+                            return (tryAgain result |> not, result)
+                        } |> Async.StartAsTask |> FirstCall
                 match cached with
                 | SubsequentCall task ->
                     let! result = task |> Async.AwaitTask

src/Paket.Core/Dependencies/NuGetV2.fs

@@ -255,7 +255,8 @@ let parseODataEntryDetails (url,nugetURL,packageName:PackageName,version:SemVerI
         | ODataSearchResult.Match entry -> entry
 
 
-let getDetailsFromNuGetViaODataFast nugetSource (packageName:PackageName) (version:SemVerInfo) =
+let getDetailsFromNuGetViaODataFast isVersionAssumed nugetSource (packageName:PackageName) (version:SemVerInfo) =
+    let doBlacklist = not isVersionAssumed
     async {
         let normalizedVersion = version.Normalize()
         let urls =
@@ -369,24 +370,24 @@ let getDetailsFromNuGetViaODataFast nugetSource (packageName:PackageName) (versi
             | Choice1Of2 _ -> false
             | _ -> true
 
-        let! result = NuGetCache.tryAndBlacklistUrl true nugetSource tryAgain handleUrl urls
+        let! result = NuGetCache.tryAndBlacklistUrl doBlacklist true nugetSource tryAgain handleUrl urls
         match result with
         | Choice1Of2 res -> return res
         | Choice2Of2 ex -> return raise (exn("error", ex))
     }
 
 
 /// Gets package details from NuGet via OData
-let getDetailsFromNuGetViaOData nugetSource (packageName:PackageName) (version:SemVerInfo) =
-    getDetailsFromNuGetViaODataFast nugetSource packageName version
+let getDetailsFromNuGetViaOData isVersionAssumed nugetSource (packageName:PackageName) (version:SemVerInfo) =
+    getDetailsFromNuGetViaODataFast isVersionAssumed nugetSource packageName version
 
-let getDetailsFromNuGet force nugetSource packageName version =
+let getDetailsFromNuGet force isVersionAssumed nugetSource packageName version =
     getDetailsFromCacheOr
         force
         nugetSource.Url
         packageName
         version
-        (fun () -> getDetailsFromNuGetViaOData nugetSource packageName version)
+        (fun () -> getDetailsFromNuGetViaOData isVersionAssumed nugetSource packageName version)
 
 /// Uses the NuGet v2 API to retrieve all packages with the given prefix.
 let FindPackages(auth, nugetURL, packageNamePrefix, maxResults) =