tar -zxvf envi_linux.x86.tar.gz
cd envi461linux.x86
sudo mkdir /usr/local/itt
sudo mv idl708 /usr/local/itt/
sudo mv install /usr/local/itt/
sudo mv license /usr/local/itt/
cd /usr/local/itt
sudo ./install

然后拷贝license到/usr/local/itt/license，命名为license.lic，就可以运行envi。
但发现我的机器明明是64位的，怎么是按照32位模式运行的呢？
仔细查找后发现，是由于idl的启动脚本里用到了/bin/arch命令，而这个命令已经被取消了，参考ubuntu的BUG。
若不想修改脚本的话，就可以建一个/bin/arch的脚本：

#!/bin/bash
uname -m

不过现在终于找到了解决办法：

LIBGL_ALWAYS_INDIRECT=1 /usr/local/bin/envi

最终是在ITT的forum上找到了答案：

Hi there. We came across Tech Tip “OpenGL Direct Hardware Rendering on Linux. Article ID: 3524″ that showed a workaround.
Disabling (OpenGL) direct rendering made the trick (at the expense of speed):
debian10$ export LIBGL_ALWAYS_INDIRECT=1
I still wonder why other software work fine.

Cheers,
Juan P.

同时，他还给出了一种解释：

Hi there,

After talking to Xorg/DRI/Debian developers, it seems that direct rendering is working ok on my system but a conflict exists between system libGL and IDL’s own copy of Mesa.
They suggest that the system libGL and IDL’s own copy of Mesa shouldn’t be used at the same time, or that IDL should at least make sure their symbols don’t interfere with each other. They suggested a possible workaround (to start the program with LD_PRELAD=/usr/local/rsi/idl_6.3/bin/bin.linux.x86/libMesaGL6_2.so.1 or some variation thereof), which unfortunately didn’t work for me.

Cheers,
J.P. Rigol

不过这种hack方法在我的机器也不能工作。
在这个地方给出了更多的说明：

Troubleshooting
RSI cannot control driver quality, so you may have trouble with some drivers that might be buggy. Besides obtaining a driver update from the vendor, there are several things you can do to make IDL usable again in the presence of a buggy driver:

* Read the documentation that came along with your driver software carefully. There may be a number of diagnostic tools or environment variables that you can set to provide some relief.
* When using an X server based on XFree86, modifying the XFree86 configuration file may solve any problems. Consult the XFree86 documentation for details. Also, the XFree86 server startup log, usually found in /var/log, can provide many clues about the problem.
* Set the LIBGL_ALWAYS_INDIRECT environment variable. This causes OpenGL to ignore IDL’s request to use direct rendering and would then avoid any bugs that may exist in the direct path.
* Configure your IDL session to use software rendering when required or code your IDL application to use software rendering. These details are covered in IDL documentation.
* As a last resort, remove/rename the gl_driver shared library from your IDL installation (in the binary directory). This will keep IDL from attempting to use direct or indirect hardware rendering. IDL will instead perform all rendering itself and send the results to the X server with “2D” commands.
* One expert IDL programmer reported in March 2004 on the IDL Newsgroup this promising workaround on a host running Fedora Linux:
“If you’re a user of a recent Linux (like Fedora), and you’ve experienced IDL crashes that post the following fatal error:

Floating exception

when attempting to use any of IDL’s OpenGL 3D stuff (like the Demo->Itools, for example), you might try the following:
setenv MESA_NO_ASM 1

This disables some specific ASM code in the Mesa library which was causing these types of crashes for me. I use an ATI Radeon 7500 plus XFree86 4.3.0′s Radeon drivers. With this environment variable set, IDL’s 3D hardware rendering seems stable, and definitely executes much faster than the alternative software rendering option.”

现在就能解释为何在XGL环境下可以使用ENVI了：现在的XGL环境不支持OPENGL直接调用！

cd
tar -zxvf envi_linux.x86.tar.gz
sudo mkdir /usr/local/rsi
sudo mv idl_6.3 /usr/local/rsi
sudo mv install /usr/local/rsi
sudo mv license /usr/local/rsi
cd /usr/local/rsi
sudo ./install

In the install process, I choose the first option(rsi manner), and it creates some directory by ln command(my option). After the installation, I can run envi by typing command “envi” in terminal, maybe I should create a icon menu in the gnome desktop.