在BitBucket中把Mercurial/Hg仓库转换为Git仓库

当初选择BitBucket的原因是，BitBucket免费支持私有库。而且BitBucket同时支持Git和Mercurial。
当初选择Mercurial的原因是，Mercurial看起来好像比Git要简单些。
然而，今年的8月BitBucket宣布明年不再支持Mercurial了。好吧，那只能想办法把Mercurial的仓库转换为Git的了。本来想着BitBucket会提供把Mercurial库转换为Git库的功能，但是并没有（又或许是我没有找到），所以只能另想办法了。
~~[注] 刚发现，在BitBucket上新建仓库时，可以导入Mercurial库，所以……~~

幸好有好心人提供了工具，叫hg-fast-export。看起来还算简单，下面实际操作一下。

环境

Debian 10 Buster
Python 2.7.16
互联网连接

准备工具

安装Git和Mercurial

sudo apt install git mercurial

安装Mercurial的Python库

pip2 install mercurial -i https://mirrors.aliyun.com/pypi/simple/

准备本地Mercurial仓库

将BitBucket上的Mercurial库(名称170101)clone到本地。
注意：这里我使用了一个假链接，实际操作需要换成真实的

z@wn:~$ mkdir ~/hg-src
z@wn:~$ cd ~/hg-src
z@wn:~/hg-src$ hg clone https://[email protected]/project1/170101

http authorization required for https://bitbucket.org/project1/170101
realm: Bitbucket.org HTTP
user: username
password:
destination directory: 170101
requesting all changes
adding changesets
adding manifests
adding file changes
added 23 changesets with 357 changes to 140 files
new changesets 124c:826b (21 drafts)
updating to branch default
140 files updated, 0 files merged, 0 files removed, 0 files unresolved
z@wn:~/hg-src$

（如上和下面都用了https的方式，没有用ssh，因为懒得处理公钥问题）

下载hg-fast-export工具

z@wn:~$ mkdir ~/git-src/
z@wn:~$ cd ~/git-src
z@wn:~/git-src$ git clone https://github.com/frej/fast-export.git
Cloning into 'fast-export'...
remote: Enumerating objects: 31, done.
remote: Counting objects: 100% (31/31), done.
remote: Compressing objects: 100% (22/22), done.
remote: Total 1473 (delta 14), reused 26 (delta 9), pack-reused 1442
Receiving objects: 100% (1473/1473), 405.65 KiB | 71.00 KiB/s, done.
Resolving deltas: 100% (866/866), done.
z@wn:~/git-src$

转换为Git仓库

在BitBucket上新建一个空的Git的仓库，取名170101-git
在本地建立一个空的Git仓库，图方便，也取名170101-git

z@wn:~/git-src$ git init 170101-git
Initialized empty Git repository in /home/z/git-src/170101-git/.git/
z@wn:~/git-src$ cd 170101-git/
z@wn:~/git-src/170101-git$ ~/git-src/fast-export/hg-fast-export.sh -r ~/hg-src/170101
master: Exporting full revision 1/23 with 1/0/0 added/changed/removed files
master: Exporting simple delta revision 2/23 with 1/0/0 added/changed/removed files
master: Exporting simple delta revision 3/23 with 121/1/0 added/changed/removed files
master: Exporting simple delta revision 4/23 with 3/12/0 added/changed/removed files
master: Exporting simple delta revision 5/23 with 0/9/0 added/changed/removed files
master: Exporting simple delta revision 6/23 with 0/6/0 added/changed/removed files
master: Exporting simple delta revision 7/23 with 0/4/0 added/changed/removed files
master: Exporting simple delta revision 8/23 with 0/13/0 added/changed/removed files
master: Exporting simple delta revision 9/23 with 0/9/0 added/changed/removed files
master: Exporting simple delta revision 10/23 with 0/5/0 added/changed/removed files
master: Exporting simple delta revision 11/23 with 0/23/0 added/changed/removed files
master: Exporting simple delta revision 12/23 with 0/6/0 added/changed/removed files
master: Exporting simple delta revision 13/23 with 0/13/0 added/changed/removed files
master: Exporting simple delta revision 14/23 with 0/12/0 added/changed/removed files
master: Exporting simple delta revision 15/23 with 0/7/0 added/changed/removed files
master: Exporting simple delta revision 16/23 with 3/19/0 added/changed/removed files
master: Exporting simple delta revision 17/23 with 11/9/0 added/changed/removed files
master: Exporting simple delta revision 18/23 with 0/23/0 added/changed/removed files
master: Exporting simple delta revision 19/23 with 0/7/0 added/changed/removed files
master: Exporting simple delta revision 20/23 with 0/12/0 added/changed/removed files
master: Exporting simple delta revision 21/23 with 0/8/0 added/changed/removed files
master: Exporting simple delta revision 22/23 with 0/18/0 added/changed/removed files
master: Exporting simple delta revision 23/23 with 0/1/0 added/changed/removed files
Issued 23 commands
/usr/lib/git-core/git-fast-import statistics:
---------------------------------------------------------------------
Alloc'd objects:       5000
Total objects:          514 (        16 duplicates                  )
      blobs  :          341 (        16 duplicates        224 deltas of        339 attempts)
      trees  :          150 (         0 duplicates        121 deltas of        138 attempts)
      commits:           23 (         0 duplicates          0 deltas of          0 attempts)
      tags   :            0 (         0 duplicates          0 deltas of          0 attempts)
Total branches:           1 (         1 loads     )
      marks:           1024 (        23 unique    )
      atoms:            149
Memory total:          2344 KiB
       pools:          2110 KiB
     objects:           234 KiB
---------------------------------------------------------------------
pack_report: getpagesize()            =       4096
pack_report: core.packedGitWindowSize = 1073741824
pack_report: core.packedGitLimit      = 35184372088832
pack_report: pack_used_ctr            =          2
pack_report: pack_mmap_calls          =          1
pack_report: pack_open_windows        =          1 /          1
pack_report: pack_mapped              =    2083265 /    2083265
---------------------------------------------------------------------

z@wn:~/git-src/170101-git$

转换时为了保证汉字不出现乱码，linux系统中语言和编码有关的环境变量需要设定为UTF-8
因为转换工具不会自动checkout仓库里文件的最新版本，所以需要执行一下checkout，否则工作目录会是空的

git checkout HEAD

然后添加BitBucket的远程仓库，接着push一下。
注意：这里我使用了一个假链接，实际操作需要换成真实的

z@wn:~/git-src/170101-git$ git remote add origin https://[email protected]/project1/170101-git.git
z@wn:~/git-src/170101-git$ git push -u origin master
Password for 'https://[email protected]':
Enumerating objects: 514, done.
Counting objects: 100% (514/514), done.
Delta compression using up to 4 threads
Compressing objects: 100% (168/168), done.
Writing objects: 100% (514/514), 1.99 MiB | 236.00 KiB/s, done.
Total 514 (delta 345), reused 514 (delta 345)
remote: Resolving deltas: 100% (345/345), done.
To https://bitbucket.org/project1/170101-git.git
 * [new branch]      master -> master
Branch 'master' set up to track remote branch 'master' from 'origin'.
z@wn:~/git-src/170101-git$