This beahvior is caused by the fact that not all nuget server expose the same set of API. The full set of possibly implemented APIs is defined here.
Let's compare the service index of nuget.org with the one of GitHub. The one of nuget.org is available here and it contains a very extensive set of APIs.
{
"version": "3.0.0",
"resources": [
{
"@id": "https://azuresearch-usnc.nuget.org/query",
"@type": "SearchQueryService",
"comment": "Query endpoint of NuGet Search service (primary)"
},
{
"@id": "https://azuresearch-ussc.nuget.org/query",
"@type": "SearchQueryService",
"comment": "Query endpoint of NuGet Search service (secondary)"
},
{
"@id": "https://azuresearch-usnc.nuget.org/autocomplete",
"@type": "SearchAutocompleteService",
"comment": "Autocomplete endpoint of NuGet Search service (primary)"
},
{
"@id": "https://azuresearch-ussc.nuget.org/autocomplete",
"@type": "SearchAutocompleteService",
"comment": "Autocomplete endpoint of NuGet Search service (secondary)"
},
{
"@id": "https://azuresearch-usnc.nuget.org/",
"@type": "SearchGalleryQueryService/3.0.0-rc",
"comment": "Azure Website based Search Service used by Gallery (primary)"
},
{
"@id": "https://azuresearch-ussc.nuget.org/",
"@type": "SearchGalleryQueryService/3.0.0-rc",
"comment": "Azure Website based Search Service used by Gallery (secondary)"
},
{
"@id": "https://api.nuget.org/v3/registration5-semver1/",
"@type": "RegistrationsBaseUrl",
"comment": "Base URL of Azure storage where NuGet package registration info is stored"
},
{
"@id": "https://api.nuget.org/v3-flatcontainer/",
"@type": "PackageBaseAddress/3.0.0",
"comment": "Base URL of where NuGet packages are stored, in the format https://api.nuget.org/v3-flatcontainer/{id-lower}/{version-lower}/{id-lower}.{version-lower}.nupkg"
},
{
"@id": "https://www.nuget.org/api/v2",
"@type": "LegacyGallery"
},
{
"@id": "https://www.nuget.org/api/v2",
"@type": "LegacyGallery/2.0.0"
},
{
"@id": "https://www.nuget.org/api/v2/package",
"@type": "PackagePublish/2.0.0"
},
{
"@id": "https://www.nuget.org/api/v2/symbolpackage",
"@type": "SymbolPackagePublish/4.9.0",
"comment": "The gallery symbol publish endpoint."
},
{
"@id": "https://azuresearch-usnc.nuget.org/query",
"@type": "SearchQueryService/3.0.0-rc",
"comment": "Query endpoint of NuGet Search service (primary) used by RC clients"
},
{
"@id": "https://azuresearch-ussc.nuget.org/query",
"@type": "SearchQueryService/3.0.0-rc",
"comment": "Query endpoint of NuGet Search service (secondary) used by RC clients"
},
{
"@id": "https://azuresearch-usnc.nuget.org/autocomplete",
"@type": "SearchAutocompleteService/3.0.0-rc",
"comment": "Autocomplete endpoint of NuGet Search service (primary) used by RC clients"
},
{
"@id": "https://azuresearch-ussc.nuget.org/autocomplete",
"@type": "SearchAutocompleteService/3.0.0-rc",
"comment": "Autocomplete endpoint of NuGet Search service (secondary) used by RC clients"
},
{
"@id": "https://api.nuget.org/v3/registration5-semver1/",
"@type": "RegistrationsBaseUrl/3.0.0-rc",
"comment": "Base URL of Azure storage where NuGet package registration info is stored used by RC clients. This base URL does not include SemVer 2.0.0 packages."
},
{
"@id": "https://www.nuget.org/packages/{id}/{version}/ReportAbuse",
"@type": "ReportAbuseUriTemplate/3.0.0-rc",
"comment": "URI template used by NuGet Client to construct Report Abuse URL for packages used by RC clients"
},
{
"@id": "https://api.nuget.org/v3/registration5-semver1/{id-lower}/index.json",
"@type": "PackageDisplayMetadataUriTemplate/3.0.0-rc",
"comment": "URI template used by NuGet Client to construct display metadata for Packages using ID"
},
{
"@id": "https://api.nuget.org/v3/registration5-semver1/{id-lower}/{version-lower}.json",
"@type": "PackageVersionDisplayMetadataUriTemplate/3.0.0-rc",
"comment": "URI template used by NuGet Client to construct display metadata for Packages using ID, Version"
},
{
"@id": "https://azuresearch-usnc.nuget.org/query",
"@type": "SearchQueryService/3.0.0-beta",
"comment": "Query endpoint of NuGet Search service (primary) used by beta clients"
},
{
"@id": "https://azuresearch-ussc.nuget.org/query",
"@type": "SearchQueryService/3.0.0-beta",
"comment": "Query endpoint of NuGet Search service (secondary) used by beta clients"
},
{
"@id": "https://azuresearch-usnc.nuget.org/autocomplete",
"@type": "SearchAutocompleteService/3.0.0-beta",
"comment": "Autocomplete endpoint of NuGet Search service (primary) used by beta clients"
},
{
"@id": "https://azuresearch-ussc.nuget.org/autocomplete",
"@type": "SearchAutocompleteService/3.0.0-beta",
"comment": "Autocomplete endpoint of NuGet Search service (secondary) used by beta clients"
},
{
"@id": "https://api.nuget.org/v3/registration5-semver1/",
"@type": "RegistrationsBaseUrl/3.0.0-beta",
"comment": "Base URL of Azure storage where NuGet package registration info is stored used by Beta clients. This base URL does not include SemVer 2.0.0 packages."
},
{
"@id": "https://www.nuget.org/packages/{id}/{version}/ReportAbuse",
"@type": "ReportAbuseUriTemplate/3.0.0-beta",
"comment": "URI template used by NuGet Client to construct Report Abuse URL for packages"
},
{
"@id": "https://www.nuget.org/packages/{id}/{version}?_src=template",
"@type": "PackageDetailsUriTemplate/5.1.0",
"comment": "URI template used by NuGet Client to construct details URL for packages"
},
{
"@id": "https://api.nuget.org/v3/registration5-gz-semver1/",
"@type": "RegistrationsBaseUrl/3.4.0",
"comment": "Base URL of Azure storage where NuGet package registration info is stored in GZIP format. This base URL does not include SemVer 2.0.0 packages."
},
{
"@id": "https://api.nuget.org/v3/registration5-gz-semver2/",
"@type": "RegistrationsBaseUrl/3.6.0",
"comment": "Base URL of Azure storage where NuGet package registration info is stored in GZIP format. This base URL includes SemVer 2.0.0 packages."
},
{
"@id": "https://api.nuget.org/v3/registration5-gz-semver2/",
"@type": "RegistrationsBaseUrl/Versioned",
"clientVersion": "4.3.0-alpha",
"comment": "Base URL of Azure storage where NuGet package registration info is stored in GZIP format. This base URL includes SemVer 2.0.0 packages."
},
{
"@id": "https://api.nuget.org/v3-index/repository-signatures/4.7.0/index.json",
"@type": "RepositorySignatures/4.7.0",
"comment": "The endpoint for discovering information about this package source's repository signatures."
},
{
"@id": "https://api.nuget.org/v3-index/repository-signatures/5.0.0/index.json",
"@type": "RepositorySignatures/5.0.0",
"comment": "The endpoint for discovering information about this package source's repository signatures."
},
{
"@id": "https://api.nuget.org/v3/catalog0/index.json",
"@type": "Catalog/3.0.0",
"comment": "Index of the NuGet package catalog."
}
],
"@context": {
"@vocab": "http://schema.nuget.org/services#",
"comment": "http://www.w3.org/2000/01/rdf-schema#comment"
}
}
The one of GitHub available here contains a much more limited set of supported APIs:
{
"version": "3.0.0-beta.1",
"resources": [
{
"@id": "https://nuget.pkg.github.com/mabead/download",
"@type": "PackageBaseAddress/3.0.0",
"comment": "Get package content (.nupkg)."
},
{
"@id": "https://nuget.pkg.github.com/mabead/query",
"@type": "SearchQueryService",
"comment": "Filter and search for packages by keyword."
},
{
"@id": "https://nuget.pkg.github.com/mabead/query",
"@type": "SearchQueryService/3.0.0-beta",
"comment": "Filter and search for packages by keyword."
},
{
"@id": "https://nuget.pkg.github.com/mabead/query",
"@type": "SearchQueryService/3.0.0-rc",
"comment": "Filter and search for packages by keyword."
},
{
"@id": "https://nuget.pkg.github.com/mabead",
"@type": "PackagePublish/2.0.0",
"comment": "Push and delete (or unlist) packages."
},
{
"@id": "https://nuget.pkg.github.com/mabead",
"@type": "RegistrationsBaseUrl",
"comment": "Get package metadata."
},
{
"@id": "https://nuget.pkg.github.com/mabead",
"@type": "RegistrationsBaseUrl/3.0.0-beta",
"comment": "Get package metadata."
},
{
"@id": "https://nuget.pkg.github.com/mabead",
"@type": "RegistrationsBaseUrl/3.0.0-rc",
"comment": "Get package metadata."
}
]
}
So, the API required to execute nuget.exe list
is supported by nuget.org but not by GitHub, thus explaining the warning explained in the console.