Chocolatey reporting success when install fails with 503 error

Hi,

I experienced a silent failure while installing the dotnetfx package. I don't think the problem is with the package, as it appears to be a network failure and I managed to install the package successfully on the next run. The issue here is that I see a 'The remote server returned an error: (503) Server Unavailable. Service Unavailable' and the package was not installed, but the exit code was 0 so it reported success. This is most likely not relevant to the issue, but I am installing using the ansible win_chocolatey module. Here is the log from the failure.

16:53:30 "Chocolatey v0.10.9",
16:53:30 "Chocolatey is running on Windows v 6.3.9600.0",
16:53:30 "Attempting to delete file \"C:/ProgramData/chocolatey/choco.exe.old\".",
16:53:30 "Attempting to delete file \"C:\\ProgramData\\chocolatey\\choco.exe.old\".",
16:53:30 "Command line: \"C:\\ProgramData\\chocolatey\\choco.exe\" install -dv --no-progress -y dotnetfx --timeout 2700 --failonunfound --whatif --installargs \"--norestart --quiet --version 4.7.2 -my\"",
16:53:30 "Received arguments: install -dv --no-progress -y dotnetfx --timeout 2700 --failonunfound --whatif --installargs --norestart --quiet --version 4.7.2 -my",
16:53:30 "RemovePendingPackagesTask is now ready and waiting for PreRunMessage.",
16:53:30 "Sending message 'PreRunMessage' out if there are subscribers...",
16:53:30 "[Pending] Removing all pending packages that should not be considered installed...",
16:53:30 "The source 'https://chocolatey.org/api/v2/' evaluated to a 'normal' source type",
16:53:30 "",
16:53:30 "NOTE: Hiding sensitive configuration data! Please double and triple ",
16:53:30 " check to be sure no sensitive data is shown, especially if copying ",
16:53:30 " output to a gist for review.",
16:53:30 "Configuration: CommandName='install'|",
16:53:30 "CacheLocation='C:\\Users\\svc-hudson\\AppData\\Local\\Temp\\chocolatey'|",
16:53:30 "ContainsLegacyPackageInstalls='True'|",
16:53:30 "CommandExecutionTimeoutSeconds='2700'|WebRequestTimeoutSeconds='30'|",
16:53:30 "Sources='https://chocolatey.org/api/v2/'|SourceType='normal'|",
16:53:30 "Debug='True'|Verbose='True'|Trace='False'|Force='False'|Noop='True'|",
16:53:30 "HelpRequested='False'|UnsuccessfulParsing='False'|RegularOutput='True'|",
16:53:30 "QuietOutput='False'|PromptForConfirmation='False'|AcceptLicense='True'|",
16:53:30 "AllowUnofficialBuild='False'|Input='dotnetfx --failonunfound'|",
16:53:30 "AllVersions='False'|SkipPackageInstallProvider='False'|",
16:53:30 "PackageNames='dotnetfx'|Prerelease='False'|ForceX86='False'|",
16:53:30 "InstallArguments='--norestart --quiet --version 4.7.2 -my'|",
16:53:30 "OverrideArguments='False'|NotSilent='False'|",
16:53:30 "ApplyPackageParametersToDependencies='False'|",
16:53:30 "ApplyInstallArgumentsToDependencies='False'|IgnoreDependencies='False'|",
16:53:30 "AllowMultipleVersions='False'|AllowDowngrade='False'|",
16:53:30 "ForceDependencies='False'|Information.PlatformType='Windows'|",
16:53:30 "Information.PlatformVersion='6.3.9600.0'|",
16:53:30 "Information.PlatformName='Windows Server 2012 R2'|",
16:53:30 "Information.ChocolateyVersion='0.10.9.0'|",
16:53:30 "Information.ChocolateyProductVersion='0.10.9'|",
16:53:30 "Information.FullName='choco, Version=0.10.9.0, Culture=neutral, PublicKeyToken=79d02ea9cad655eb'|",
16:53:30 "",
16:53:30 "Information.Is64BitOperatingSystem='True'|",
16:53:30 "Information.Is64BitProcess='True'|Information.IsInteractive='False'|",
16:53:30 "Information.UserName='svc-hudson'|",
16:53:30 "Information.UserDomainName='GREENWICH'|",
16:53:30 "Information.IsUserAdministrator='True'|",
16:53:30 "Information.IsUserSystemAccount='False'|",
16:53:30 "Information.IsUserRemoteDesktop='False'|",
16:53:30 "Information.IsUserRemote='True'|",
16:53:30 "Information.IsProcessElevated='True'|",
16:53:30 "Information.IsLicensedVersion='False'|Information.LicenseType='Foss'|",
16:53:30 "Features.AutoUninstaller='True'|Features.ChecksumFiles='True'|",
16:53:30 "Features.AllowEmptyChecksums='False'|",
16:53:30 "Features.AllowEmptyChecksumsSecure='True'|",
16:53:30 "Features.FailOnAutoUninstaller='False'|",
16:53:30 "Features.FailOnStandardError='False'|Features.UsePowerShellHost='True'|",
16:53:30 "Features.LogEnvironmentValues='False'|Features.LogWithoutColor='False'|",
16:53:30 "Features.VirusCheck='False'|",
16:53:30 "Features.FailOnInvalidOrMissingLicense='False'|",
16:53:30 "Features.IgnoreInvalidOptionsSwitches='True'|",
16:53:30 "Features.UsePackageExitCodes='True'|",
16:53:30 "Features.UseFipsCompliantChecksums='False'|",
16:53:30 "Features.ShowNonElevatedWarnings='True'|",
16:53:30 "Features.ShowDownloadProgress='False'|",
16:53:30 "Features.StopOnFirstPackageFailure='False'|",
16:53:30 "Features.UseRememberedArgumentsForUpgrades='False'|",
16:53:30 "Features.IgnoreUnfoundPackagesOnUpgradeOutdated='False'|",
16:53:30 "Features.RemovePackageInformationOnUninstall='False'|",
16:53:30 "Features.ScriptsCheckLastExitCode='False'|",
16:53:30 "ListCommand.LocalOnly='False'|",
16:53:30 "ListCommand.IdOnly='False'|ListCommand.IncludeRegistryPrograms='False'|",
16:53:30 "ListCommand.PageSize='25'|ListCommand.Exact='False'|",
16:53:30 "ListCommand.ByIdOnly='False'|ListCommand.ByTagOnly='False'|",
16:53:30 "ListCommand.IdStartsWith='False'|ListCommand.OrderByPopularity='False'|",
16:53:30 "ListCommand.ApprovedOnly='False'|",
16:53:30 "ListCommand.DownloadCacheAvailable='False'|",
16:53:30 "ListCommand.NotBroken='False'|",
16:53:30 "ListCommand.IncludeVersionOverrides='False'|",
16:53:30 "UpgradeCommand.FailOnUnfound='False'|",
16:53:30 "UpgradeCommand.FailOnNotInstalled='False'|",
16:53:30 "UpgradeCommand.NotifyOnlyAvailableUpgrades='False'|",
16:53:30 "UpgradeCommand.ExcludePrerelease='False'|",
16:53:30 "NewCommand.AutomaticPackage='False'|",
16:53:30 "NewCommand.UseOriginalTemplate='False'|SourceCommand.Command='unknown'|",
16:53:30 "SourceCommand.Priority='0'|SourceCommand.BypassProxy='False'|",
16:53:30 "SourceCommand.AllowSelfService='False'|",
16:53:30 "SourceCommand.VisibleToAdminsOnly='False'|",
16:53:30 "FeatureCommand.Command='unknown'|ConfigCommand.Command='unknown'|",
16:53:30 "PinCommand.Command='unknown'|OutdatedCommand.IgnorePinned='False'|",
16:53:30 "Proxy.BypassOnLocal='True'|",
16:53:30 "_ Chocolatey:ChocolateyInstallCommand - Noop Mode _",
16:53:30 "Chocolatey would have used NuGet to install packages (if they are not already installed):",
16:53:30 "dotnetfx",
16:53:30 "Attempting to create directory \"C:\\Users\\svc-hudson\\AppData\\Local\\Temp\\chocolatey\\Chocolatey\\TempInstalls_20180627_165329_3857\".",
16:53:30 "[NuGet] Attempting to resolve dependency 'KB2919355 (≥ 1.0.20160915)'.",
16:53:30 "[NuGet] Attempting to resolve dependency 'KB2919442 (≥ 1.0.20160915)'.",
16:53:30 "dotnetfx not installed. An error occurred during installation:",
16:53:30 " The remote server returned an error: (503) Server Unavailable. Service Unavailable",
16:53:30 "Attempting to delete directory \"C:\\Users\\svc-hudson\\AppData\\Local\\Temp\\chocolatey\\Chocolatey\\TempInstalls_20180627_165329_3857\".",
16:53:30 "",
16:53:30 "Enjoy using Chocolatey? Explore more amazing features to take your",
16:53:30 "experience to the next level at",
16:53:30 " https://chocolatey.org/compare",
16:53:30 "Sending message 'PostRunMessage' out if there are subscribers...",
16:53:30 "Exiting with 0"

Start with the install command's handling of the reported NuGet resolution failure and the final "Exiting with 0" path. Reproduce a dotnetfx install against a source returning HTTP 503, then verify that the command reports failure with a nonzero exit code instead of success.

Written by the indexing model from the issue text.