Fix GitHub release creation silently dropping tag_name under Native AOT

src/release-notes/GitHubReleaseClient.cs

@@ -0,0 +1,56 @@
+using System.Net.Http.Headers;
+using System.Text.Json.Serialization;
+
+namespace ReleaseNotes;
+
+/// <summary>
+/// Minimal, source-generated-JSON client for creating a GitHub release directly against the REST API.
+/// </summary>
+/// <remarks>
+/// Octokit.Repository.Release.Create can't be used here: Octokit's SimpleJsonSerializer serializes request
+/// bodies via raw, unannotated reflection (no [DynamicallyAccessedMembers] anywhere in Octokit/SimpleJson.cs),
+/// and under Native AOT trimming the linker strips getter metadata for any property whose accessors have
+/// mixed visibility. NewRelease.TagName is "public get; private set;" - the only such property among every
+/// request model this tool sends - so in an AOT-published build tag_name silently vanishes from the outgoing
+/// JSON while every other field (all plain public get/set) still serializes fine. GitHub then rejects the
+/// request with 422 "tag_name" wasn't supplied, even though the C# call site clearly set it. Everything else
+/// this tool does through Octokit (GetLatest/Get, ReleaseUpdate, labels) uses only plain public get/set
+/// models, so those aren't affected - only the Create path needs this workaround.
+/// </remarks>
+internal static class GitHubReleaseClient
+{
+	public static async Task CreateRelease(HttpClient httpClient, string owner, string repository, string tagName, string? body, string? token)
+	{
+		using var request = new HttpRequestMessage(HttpMethod.Post, $"https://api.github.com/repos/{owner}/{repository}/releases")
+		{
+			Content = System.Net.Http.Json.JsonContent.Create(
+				new GitHubNewReleaseRequest { TagName = tagName, Body = body },
+				GitHubReleaseJsonContext.Default.GitHubNewReleaseRequest)
+		};
+		request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/vnd.github+json"));
+		request.Headers.UserAgent.Add(new ProductInfoHeaderValue("ReleaseNotesGenerator", "1.0"));
+		request.Headers.Add("X-GitHub-Api-Version", "2022-11-28");
+		if (token is { Length: > 0 })
+			request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
+
+		using var response = await httpClient.SendAsync(request);
+		if (!response.IsSuccessStatusCode)
+		{
+			var responseBody = await response.Content.ReadAsStringAsync();
+			throw new InvalidOperationException(
+				$"Failed to create GitHub release for tag '{tagName}' on {owner}/{repository}: {(int)response.StatusCode} {response.StatusCode}\n{responseBody}");
+		}
+	}
+}
+
+internal sealed class GitHubNewReleaseRequest
+{
+	[JsonPropertyName("tag_name")]
+	public required string TagName { get; set; }
+
+	[JsonPropertyName("body")]
+	public string? Body { get; set; }
+}
+
+[JsonSerializable(typeof(GitHubNewReleaseRequest))]
+internal partial class GitHubReleaseJsonContext : JsonSerializerContext;

src/release-notes/ReleaseNotesRunner.cs

@@ -51,7 +51,12 @@ private static async Task CreateRelease(ReleaseNotesConfig config, GitHubClient
 			await client.Repository.Release.Edit(config.GitHub.Owner, config.GitHub.Repository, existing.Id, new ReleaseUpdate { Body = body.ToString() });
 		}
 		else
-			await client.Repository.Release.Create(config.GitHub.Owner, config.GitHub.Repository, new NewRelease(config.Version) { Body = body.ToString() });
+		{
+			// Not client.Repository.Release.Create() - see GitHubReleaseClient's remarks for why Octokit's
+			// own NewRelease serialization silently drops tag_name under Native AOT.
+			using var httpClient = new HttpClient();
+			await GitHubReleaseClient.CreateRelease(httpClient, config.GitHub.Owner, config.GitHub.Repository, config.Version, body.ToString(), config.Token);
+		}
 	}
 
 	private static async Task<string?> LocateOldVersion(ReleaseNotesConfig config, GitHubClient client)