Maven打包錯誤：Failed to execute goal on project client: Could not resolve dependencies for project

我先說下我的打包步驟

一、復現

我的應用中有兩個模塊：client和common
其中client依賴common

打包步驟

先打包common，build success
再打包client，此時出錯！錯誤信息如下

[INFO] Scanning for projects...
[INFO] 
[INFO] -------------------------< org.example:client >-------------------------
[INFO] Building client 1.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  0.309 s
[INFO] Finished at: 2020-06-17T16:58:00+08:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project client: Could not resolve dependencies for project org.example:client:jar:1.0-SNAPSHOT: Failed to collect dependencies at org.example:common:jar:1.0-SNAPSHOT: Failed to read artifact descriptor for org.example:common:jar:1.0-SNAPSHOT: Could not find artifact org.example:project-test:pom:1.0-SNAPSHOT -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException

二、排查

上面錯誤信息中，有兩行提示，我們摘出來

## 查看完整錯誤棧信息，可以添加-e 參數
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
## 查看完整的debug日誌，可以添加-X 參數
[ERROR] Re-run Maven using the -X switch to enable full debug logging.

1. 使用-e參數重新install

我們進入到client文件夾下，使用-e參數重新打包試試，看看它的異常棧信息

cd client
mvn clean install -e

2. 查看異常棧

異常棧很長查看最後一個即可，錯誤棧截圖如下

清晰明瞭，打包異常的原因，就是因爲沒有找到org.example:project-test:pom:1.0-SNAPSHOT這個包！

三、解決

上面異常棧中org.example:project-test:pom:1.0-SNAPSHOT這個包，也就是子模塊的父項目，即項目本身project-test。打包一下這個父項目，就能解決了。

結論

client打包時依賴common，而common依賴父工程project-test。
所以client先去本地查找project-test這個包；沒找到就去私服中找，肯定還沒找到；進而去中央倉庫查找，還是沒找到，就報錯了！

四、授之以漁

1. 遇到打包錯誤的情況不要慌，直接加-X或者-e參數重新打包，看看錯誤日誌是什麼，一般都會顯示很清楚的。
   -X 參數：顯示打包過程中的debug日誌
   -e 參數：顯示完成錯誤棧信息
2. 仔細看錯誤信息
   我們把最初的報錯信息再摘出來一段：
   [ERROR] Failed to execute goal on project client: Could not resolve dependencies for project org.example:client:jar:1.0-SNAPSHOT: Failed to collect dependencies at org.example:common:jar:1.0-SNAPSHOT: Failed to read artifact descriptor for org.example:common:jar:1.0-SNAPSHOT: Could not find artifact org.example:project-test:pom:1.0-SNAPSHOT -> [Help 1]
   直接看最後一個錯誤，也能很清晰的看到提示缺少project-test:pom:1.0-SNAPSHOT這個包。