我终于想通了!
打开git-svn文件（perl脚本，在我的例子中文件位置是/usr/local/opt/git/libexec/git-core/git-svn），将第一行#!/usr/bin/perl更改为#!/usr/local/bin/perl
而且很管用!
我猜system perl没有包含perl SVN/Core，但是brew perl有（brew svn的依赖项）。

• • 适用于MacOS Big Sur 11.5的解决方案**

在与此错误斗争了几个小时后：

Can't locate SVN/Core.pm in @INC (you may need to install the SVN::Core module)

我终于找到了一个有效的解决办法。
如果运行：

brew reinstall subversion

它将打印如下消息：

The perl bindings are located in various subdirectories of:
  /usr/local/opt/subversion/lib/perl5

然后，在使用git svn从正确的路径加载SVN模块之前，您只需要运行以下命令：

export PERL5LIB=/usr/local/opt/subversion/lib/perl5/site_perl/5.30.2/darwin-thread-multi-2level

解决方案对于那些，像我一样-想要使用macOS Catalina上的sourcetree客户端与git-svn：
第一步：

brew install git
brew install perl
brew install subversion

edit
/usr/local/Cellar/git/git_version/libexec/git-core/git-svn
replace
#!/usr/bin/perl
with
#!/usr/local/bin/perl

第二步，安装缺少的Perl模块：

cpan SVN::Core
cpan Term::ReadKey

第三步，配置源树：
在资源树-〉首选项-设置选项"使用系统git"，从：

/usr/local/Cellar/git/git_version/git

虽然不是永久性修复，但解决方法是设置${GITPERLLIB}：

$ export GITPERLLIB=/usr/local/Cellar/git/2.31.1/share/perl5:/usr/local/lib/perl5/site_perl/5.28.2/darwin-thread-multi-2level
$ git svn clone svn+ssh://...

为我工作，没有编辑任何脚本安装的brew。

确保您已通过Homebrew安装Perl、Subversion和依赖项：

brew install perl subversion apr apr-util

将所需的Perl模块安装到~/perl5中：

export PATH="/usr/local/opt/apr/bin:/usr/local/opt/apr-util/bin:$PATH"
PERL_MM_OPT="INSTALL_BASE=$HOME/perl5" cpan local::lib Git::SVN SVN::Core

通过以下方式验证安装的模块：

PERL5LIB="$HOME/perl5" cpan -l | grep SVN

然后按如下所示配置Perl（基于brew info perl步骤）：

eval "$(perl -I$HOME/perl5/lib/perl5 -Mlocal::lib=$HOME/perl5)"

最后运行Git的SVN：

PERLLIB="$HOME/perl5" git svn clone https://svn.somecode.example.com/svn/trunk

如果你仍然卡住，尝试GitHub和GitLab网站，他们提供了Git/SVN迁移。
例如，在GitHub中，创建一个新的仓库，然后通过粘贴旧仓库的克隆URL导入项目。

错误消息显示：

$ git svn --version
Can't locate SVN/Core.pm in @INC (you may need to install the SVN::Core module) (@INC contains: /usr/local/opt/subversion/lib/perl5 /usr/local/Cellar/git/2.31.1/share/perl5 /Applications/Xcode.app/Contents/Developer/Library/Perl/5.28/darwin-thread-multi-2level /Library/Developer/CommandLineTools/Library/Perl/5.28/darwin-thread-multi-2level /Library/Perl/5.30/darwin-thread-multi-2level /Library/Perl/5.30 /Network/Library/Perl/5.30/darwin-thread-multi-2level /Network/Library/Perl/5.30 /Library/Perl/Updates/5.30.2 /System/Library/Perl/5.30/darwin-thread-multi-2level /System/Library/Perl/5.30 /System/Library/Perl/Extras/5.30/darwin-thread-multi-2level /System/Library/Perl/Extras/5.30) at /usr/local/Cellar/git/2.31.1/share/perl5/Git/SVN/Utils.pm line 6.
BEGIN failed--compilation aborted at /usr/local/Cellar/git/2.31.1/share/perl5/Git/SVN/Utils.pm line 6.
Compilation failed in require at /usr/local/Cellar/git/2.31.1/share/perl5/Git/SVN.pm line 25.
BEGIN failed--compilation aborted at /usr/local/Cellar/git/2.31.1/share/perl5/Git/SVN.pm line 32.
Compilation failed in require at /usr/local/Cellar/git/2.31.1/libexec/git-core/git-svn line 23.
BEGIN failed--compilation aborted at /usr/local/Cellar/git/2.31.1/libexec/git-core/git-svn line 23.

这是因为git-svn是由Perl实现的，它需要一个名为SVN::Core的Perl库来运行.将git-svn脚本的第一行从#!/usr/bin/perl修改为#!/usr/local/bin/perl**不会修复这个错误!!! * 因为这只是将Perl库从system default version修改为brew installed version.如果brew installed version不包含SVN::Core，它仍然会失败：

$ git svn --version
Can't locate SVN/Core.pm in @INC (you may need to install the SVN::Core module) (@INC contains: /usr/local/Cellar/git/2.31.1/share/perl5 /Applications/Xcode.app/Contents/Developer/Library/Perl/5.28/darwin-thread-multi-2level /Library/Developer/CommandLineTools/Library/Perl/5.28/darwin-thread-multi-2level /usr/local/Cellar/perl/5.34.0/lib/perl5/site_perl/5.34.0/darwin-thread-multi-2level /usr/local/Cellar/perl/5.34.0/lib/perl5/site_perl/5.34.0 /usr/local/Cellar/perl/5.34.0/lib/perl5/5.34.0/darwin-thread-multi-2level /usr/local/Cellar/perl/5.34.0/lib/perl5/5.34.0 /usr/local/lib/perl5/site_perl/5.34.0/darwin-thread-multi-2level /usr/local/lib/perl5/site_perl/5.34.0) at /usr/local/Cellar/git/2.31.1/share/perl5/Git/SVN/Utils.pm line 6.
BEGIN failed--compilation aborted at /usr/local/Cellar/git/2.31.1/share/perl5/Git/SVN/Utils.pm line 6.
Compilation failed in require at /usr/local/Cellar/git/2.31.1/share/perl5/Git/SVN.pm line 25.
BEGIN failed--compilation aborted at /usr/local/Cellar/git/2.31.1/share/perl5/Git/SVN.pm line 32.
Compilation failed in require at /usr/local/Cellar/git/2.31.1/libexec/git-core/git-svn line 23.
BEGIN failed--compilation aborted at /usr/local/Cellar/git/2.31.1/libexec/git-core/git-svn line 23.

注意，Perl版本已经更改，但是错误仍然存在，因为@INC指示的目录中没有SVN:Core。
现在一些答案可能会告诉您按cpan SVN::Core安装SVN::Core，**不要这样做!!!**这不会解决问题!因为它安装的SVN::Core版本可能与您的SVN版本不匹配：

$ git svn --version
error: git-svn died of signal 11

顺便说一下，cpan是垃圾，不要用它来安装任何东西。它在安装前编译源代码，但不能控制编译标志/选项，而且它不能卸载自己安装的东西。

• • 以下是正确的解决方案：**

在安装svn时已经安装了相应的Perl库，并且brew已经告诉您：

$ brew info svn
subversion: stable 1.14.1 (bottled), HEAD
Version control system designed to be a better CVS
https://subversion.apache.org/
/usr/local/Cellar/subversion/1.14.1_2 (234 files, 32.1MB) *
  Poured from bottle on 2021-06-02 at 15:52:30
From: https://mirrors.ustc.edu.cn/homebrew-core.git/Formula/subversion.rb
License: Apache-2.0
==> Dependencies
Build: openjdk ✘, pkg-config ✘, python@3.9 ✔, scons ✘, swig ✘
Required: apr ✔, apr-util ✔, gettext ✔, lz4 ✔, openssl@1.1 ✔, utf8proc ✔
==> Options
--HEAD
    Install HEAD version
==> Caveats
svntools have been installed to:
  /usr/local/opt/subversion/libexec

The perl bindings are located in various subdirectories of:
  /usr/local/opt/subversion/lib/perl5

You may need to link the Java bindings into the Java Extensions folder:
  sudo mkdir -p /Library/Java/Extensions
  sudo ln -s /usr/local/lib/libsvnjavahl-1.dylib /Library/Java/Extensions/libsvnjavahl-1.dylib
==> Analytics
install: 33,749 (30 days), 67,978 (90 days), 239,148 (365 days)
install-on-request: 33,129 (30 days), 67,011 (90 days), 229,097 (365 days)
build-error: 0 (30 days)

我们可以看到Perl绑定位于/usr/local/opt/subversion/lib/perl5中，我们只需要让git-svn使用这个路径。稍微研究一下git-svn脚本，我们可以看到这个行为是由一个名为GITPERLLIB的环境变量控制的：

$ head /usr/local/Cellar/git/2.31.1/libexec/git-core/git-svn
#!/usr/bin/perl

use lib (split(/:/, $ENV{GITPERLLIB} || '/usr/local/Cellar/git/2.31.1/share/perl5:/Applications/Xcode.app/Contents/Developer/Library/Perl/5.28/darwin-thread-multi-2level:/Library/Developer/CommandLineTools/Library/Perl/5.28/darwin-thread-multi-2level'));
# Copyright (C) 2006, Eric Wong <normalperson@yhbt.net>
# License: GPL v2 or later

因此，解决此问题的正确方法是将以下代码添加到bashrc或zshrc：

export GITPERLLIB=/usr/local/opt/subversion/lib/perl5/site_perl/$<your_perl_version>/darwin-thread-multi-2level

问题解决了!