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Created October 19, 2025 12:51
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vscode haskell extension / ghcup
Raw
discuss.txt
╭─── Claude Code v2.0.22 ─────────────────────────────────────────────────────────────────────────────────╮
│ │ Tips for getting started │
│ Welcome back LCamel! │ Run /init to create a CLAUDE.md file with instructions for Claude │
│ │ ───────────────────────────────────────────────────────────────── │
│ ▐▛███▜▌ │ Recent activity │
│ ▝▜█████▛▘ │ No recent activity │
│ ▘▘ ▝▝ │ │
│ │ │
│ Sonnet 4.5 · Claude Pro │ │
│ /Users/lcamel/vc/vscode-haskell │ │
╰─────────────────────────────────────────────────────────────────────────────────────────────────────────╯
> 我在一個乾淨的目錄裡面開啟 vscode Haskell extension, 沒有任何設定.
我想知道為什麼 extension 選擇安裝了這些工具的這些版本.
參考 a.txt 中的 log.
⏺ 我來幫您分析 vscode-haskell extension 選擇這些工具版本的原因。讓我先讀取 a.txt 的內容。
⏺ Read(a.txt)
⎿  Read 60 lines
⏺ 根據 log 分析,extension 選擇這些版本的邏輯如下:
版本選擇流程
1. 查詢可用版本 (第 7-31 行):
- Extension 通過 ghcup list 命令查詢每個工具的已安裝和可用版本
- 查詢的工具包括:hls (Haskell Language Server)、cabal、stack、ghc
2. 選擇的版本 (第 34-54 行):
- HLS: 2.11.0.0
- Cabal: 3.16.0.0
- Stack: 3.7.1
- GHC: 9.6.7
3. 檢查是否已安裝 (第 34-54 行):
- Extension 嘗試用 ghcup whereis 檢查這些版本是否已安裝
- 結果都顯示未安裝 (error code 30)
4. 用戶確認並安裝 (第 56-59 行):
- Extension 彈出提示請用戶確認下載
- 用戶接受後,執行 ghcup run 安裝所有工具
版本決定邏輯
要了解 extension 如何決定這些特定版本,讓我查看相關源代碼:
⏺ Search(pattern: "recommended|latest|default.*version", glob: "**/*.ts")
⎿  Found 4 files (ctrl+o to expand)
⏺ Search(pattern: "**/ghcup*.ts")
⎿  Found 1 file (ctrl+o to expand)
⏺ Search(pattern: "whereis.*hls|list.*hls.*available", glob: "**/*.ts")
⎿  Found 0 files
⏺ Read(src/ghcup.ts)
⎿  Read 218 lines
⏺ Read(src/metadata.ts)
⎿  Read 198 lines
⏺ Search(pattern: "getLatestAvailableVersion|findLatestUserInstalledTool", glob: "**/*.ts")
⎿  Found 2 files (ctrl+o to expand)
⏺ Read(src/hlsBinaries.ts)
⎿  Read 571 lines
⏺ 完美！現在我理解整個版本選擇的邏輯了。讓我整理給您:
Extension 版本選擇的完整邏輯
1. HLS (Haskell Language Server) 版本選擇
根據 src/hlsBinaries.ts:179-190 和 src/ghcup.ts:102-111:
if (latestHLS === undefined) {
latestHLS = await ghcup.getAnyLatestVersion('hls').then((tool) => tool?.version);
}
getAnyLatestVersion 的邏輯 (src/ghcup.ts:102-111):
1. 先檢查已安裝的版本,取最新的
2. 如果沒有已安裝的版本,則調用 getLatestAvailableVersion
3. getLatestAvailableVersion (src/ghcup.ts:121-136) 默認查找帶有 "latest" 標籤的版本
結論: HLS 2.11.0.0 是 ghcup 標記為 "latest" 的版本
2. Cabal 和 Stack 版本選擇
根據 src/hlsBinaries.ts:182-187:
if (latestCabal === undefined) {
latestCabal = (await ghcup.findLatestUserInstalledTool('cabal')).version;
}
if (latestStack === undefined) {
latestStack = (await ghcup.findLatestUserInstalledTool('stack')).version;
}
findLatestUserInstalledTool 的邏輯 (src/ghcup.ts:154-161):
1. 先嘗試獲取 set 的版本 (通過 ghcup set 設定的)
2. 如果沒有,則使用 getAnyLatestVersion (優先已安裝,否則取帶 "latest" 標籤的可用版本)
結論: Cabal 3.16.0.0 和 Stack 3.7.1 是 ghcup 標記為 "latest" 的版本
3. GHC 版本選擇
根據 src/hlsBinaries.ts:188-190:
if (recGHC === undefined) {
recGHC = !executableExists('ghc') ?
(await ghcup.getLatestAvailableVersion('ghc', 'recommended')).version : null;
}
這裡特別使用了 'recommended' 標籤而非 'latest'。
結論: GHC 9.6.7 是 ghcup 標記為 "recommended" 的版本
總結
Extension 選擇這些版本的原因:
- HLS 2.11.0.0: ghcup metadata 中標記為 latest 的 HLS 版本
- Cabal 3.16.0.0: ghcup metadata 中標記為 latest 的 Cabal 版本
- Stack 3.7.1: ghcup metadata 中標記為 latest 的 Stack 版本
- GHC 9.6.7: ghcup metadata 中標記為 recommended 的 GHC 版本 (注意不是 latest,而是 recommended,這是為了穩定性)
這些標籤來自 ghcup 的 metadata 文件 (通常從 https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ 獲取),extension 完全依賴 ghcup
社群維護的這些標籤來決定版本。
> 可是 hls 不見得搭配哪一版的 ghc 都能工作. 這樣現在是拿 latest hls 加上一個 recommended ghc 而已嗎?
⏺ 非常好的問題！您說得對,這樣會有相容性問題。讓我再仔細看一下代碼,因為實際上 extension 做了兩階段的工具鏈安裝。
⏺ Read(src/hlsBinaries.ts)
⎿  Read 150 lines
⏺ 沒錯！我發現了關鍵邏輯。Extension 使用了兩階段安裝來解決相容性問題:
兩階段工具鏈安裝策略
第一階段: Bootstrap Toolchain (第 243-261 行)
// our preliminary toolchain
const latestToolchainBindir = await ghcup.call([
'run',
...(latestHLS ? ['--hls', latestHLS] : []),
...(latestCabal ? ['--cabal', latestCabal] : []),
...(latestStack ? ['--stack', latestStack] : []),
...(recGHC ? ['--ghc', recGHC] : []),
'--install',
], 'Installing latest toolchain for bootstrap', ...);
目的: 這是一個臨時的 "bootstrap" 工具鏈,只是用來:
- 提供 cabal/stack 來分析專案
- 提供一個可用的 GHC (可能不是專案需要的版本)
您在 log 第 56 行看到的就是這個階段:
User accepted download for hls-2.11.0.0, cabal-3.16.0.0, stack-3.7.1, ghc-9.6.7.
第二階段: Project-Specific Toolchain (第 263-331 行)
關鍵在 getLatestProjectHls 函數 (src/hlsBinaries.ts:383-420)。讓我看一下這個函數的細節:
⏺ Read(src/hlsBinaries.ts)
⎿  Read 40 lines
⏺ 完美！現在看清楚了。讓我解釋完整的相容性處理邏輯:
完整的版本選擇與相容性處理
您的情況 (空白專案目錄)
在您的 a.txt log 中,因為是空白目錄沒有專案,所以:
1. 第一階段 Bootstrap (log 第 56 行):
- 安裝 hls-2.11.0.0 (latest)
- 安裝 cabal-3.16.0.0 (latest)
- 安裝 stack-3.7.1 (latest)
- 安裝 ghc-9.6.7 (recommended)
2. 第二階段 (src/hlsBinaries.ts:391-399):
- 嘗試用 haskell-language-server-wrapper --project-ghc-version 偵測專案需要的 GHC 版本
- 因為沒有專案,會 fallback 到剛安裝的 ghc-9.6.7
3. 相容性檢查 (src/hlsBinaries.ts:401-413):
- 從 HLS metadata 取得相容性對照表 (哪個 HLS 版本支援哪些 GHC 版本)
- 過濾出能支援專案 GHC 版本的所有 HLS 版本: .filter(([_k, v]) => v.some((x) => x === projectGhc))
- 排序後取最新的那個 HLS: .sort(...).pop()
- 在您的情況下,因為 projectGhc = 9.6.7,且 HLS 2.11.0.0 支援 GHC 9.6.7,所以最終還是選 2.11.0.0
如果是有專案的情況
假設您的專案 cabal.project 或 stack.yaml 指定要用 GHC 9.2.8:
1. 第一階段: 同樣先安裝 latest/recommended 版本作為 bootstrap
2. 第二階段:
- getProjectGhcVersion 會讀取專案設定,發現需要 GHC 9.2.8
- 從 metadata 過濾出支援 GHC 9.2.8 的所有 HLS 版本
- 可能發現 HLS 2.11.0.0 不支援 GHC 9.2.8
- 最終可能選擇較舊的 HLS 版本 (例如 2.6.0.0)
3. 第三次安裝: 安裝真正相容的版本組合
總結
您最初的理解是對的 - 不是隨便拿 latest HLS + recommended GHC。真正的邏輯是:
1. 先安裝 latest/recommended (用於 bootstrap)
2. 偵測專案實際需要的 GHC 版本 (從 cabal/stack 設定檔)
3. 查詢 HLS metadata (從 src/metadata.ts:137 的 ghcup-metadata 取得相容性對照表)
4. 找出支援該 GHC 的最新 HLS 版本
5. 可能會降級或升級 HLS,以確保相容
在您的空白目錄情況下,因為沒有專案設定,所以 fallback 到 bootstrap 的版本,剛好 HLS 2.11.0.0 支援 GHC 9.6.7,所以看起來像是直接用了 latest +
recommended,但其實有經過相容性檢查。
Raw
zzz.log
2025-10-19 04:49:56.9890000 [client] INFO Finding haskell-language-server
2025-10-19 04:49:56.9900000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:56.9910000 [client] INFO probing for GHCup binary
2025-10-19 04:49:56.9940000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose upgrade' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.0270000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.0290000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.0300000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose list -t hls -c installed -r' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.1300000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.1310000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.1330000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose list -t hls -c available -r' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.1980000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.1990000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.2000000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose list -t cabal -c set -r' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.2820000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.2830000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.2850000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose list -t cabal -c installed -r' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.3170000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.3190000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.3200000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose list -t cabal -c available -r' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.3530000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.3540000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.3550000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose list -t stack -c set -r' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.3880000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.3900000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.3910000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose list -t stack -c installed -r' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.4240000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.4250000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.4260000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose list -t stack -c available -r' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.4610000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.4610000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.4620000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose list -t ghc -c available -r' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.4960000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.4980000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.4980000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose whereis hls 2.11.0.0' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.5120000 [client] ERROR Error executing '/home/vscode/.ghcup/bin/ghcup --no-verbose whereis hls 2.11.0.0' with error code 30
2025-10-19 04:49:57.5120000 [client] ERROR stderr: [ Error ] []8;;https://errors.haskell.org/messages/GHCup-00130\GHCup-00130]8;;\] The version '2.11.0.0' of the tool hls is not installed.
2025-10-19 04:49:57.5120000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.5130000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.5140000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose whereis cabal 3.16.0.0' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.5280000 [client] ERROR Error executing '/home/vscode/.ghcup/bin/ghcup --no-verbose whereis cabal 3.16.0.0' with error code 30
2025-10-19 04:49:57.5280000 [client] ERROR stderr: [ Error ] []8;;https://errors.haskell.org/messages/GHCup-00130\GHCup-00130]8;;\] The version '3.16.0.0' of the tool cabal is not installed.
2025-10-19 04:49:57.5280000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.5290000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.5300000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose whereis stack 3.7.1' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.5430000 [client] ERROR Error executing '/home/vscode/.ghcup/bin/ghcup --no-verbose whereis stack 3.7.1' with error code 30
2025-10-19 04:49:57.5430000 [client] ERROR stderr: [ Error ] []8;;https://errors.haskell.org/messages/GHCup-00130\GHCup-00130]8;;\] The version '3.7.1' of the tool stack is not installed.
2025-10-19 04:49:57.5440000 [client] INFO Checking for ghcup installation
2025-10-19 04:49:57.5450000 [client] INFO probing for GHCup binary
2025-10-19 04:49:57.5460000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose whereis ghc 9.6.7' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
2025-10-19 04:49:57.5590000 [client] ERROR Error executing '/home/vscode/.ghcup/bin/ghcup --no-verbose whereis ghc 9.6.7' with error code 30
2025-10-19 04:49:57.5590000 [client] ERROR stderr: [ Error ] []8;;https://errors.haskell.org/messages/GHCup-00130\GHCup-00130]8;;\] The version '9.6.7' of the tool ghc is not installed.
2025-10-19 04:50:07.1000000 [client] INFO User accepted download for hls-2.11.0.0, cabal-3.16.0.0, stack-3.7.1, ghc-9.6.7.
2025-10-19 04:50:07.1010000 [client] INFO Checking for ghcup installation
2025-10-19 04:50:07.1050000 [client] INFO probing for GHCup binary
2025-10-19 04:50:07.1080000 [client] INFO Executing '/home/vscode/.ghcup/bin/ghcup --no-verbose run --hls 2.11.0.0 --cabal 3.16.0.0 --stack 3.7.1 --ghc 9.6.7 --install' in cwd '/vscode/vscode-server/bin/linux-arm64/7d842fb85a0275a4a8e4d7e040d2625abbf7f084'
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