How to resolve NameError: name 'pysam' is not defined?

[Stevenleizheng]

When i use this tool named CheckM, i have an issue that NameError: name 'pysam' is not defined. The detail error is seen below:

Unexpected` error: <class 'NameError'>
Traceback (most recent call last):
  File "/home/xxx/mambaforge/envs/menzmap/bin/checkm", line 856, in <module>
    checkmParser.parseOptions(args)
  File "/home/xxx/mambaforge/envs/menzmap/lib/python3.8/site-packages/checkm/main.py", line 1013, in parseOptions
    self.coverage(options)
  File "/home/xxx/mambaforge/envs/menzmap/lib/python3.8/site-packages/checkm/main.py", line 746, in coverage
    coverage.run(binFiles, options.bam_files, options.output_file, options.all_reads,
  File "/home/xxx/mambaforge/envs/menzmap/lib/python3.8/site-packages/checkm/coverage.py", line 91, in run
    coverageInfo[bamFile] = self._processBam(bamFile, bAllReads, minAlignPer, maxEditDistPer, minQC, coverageInfo[bamFile])
  File "/home/xxx/mambaforge/envs/menzmap/lib/python3.8/site-packages/checkm/coverage.py", line 131, in _processBam
    bamfile = pysam.Samfile(bamFile, 'rb')
NameError: name 'pysam' is not defined

This error is belong to the software of checkm. I will address this issue if i add a command named import pysam into the head of /home/xxx/mambaforge/envs/menzmap/lib/python3.8/site-packages/checkm/coverage.py file and then delete original command import pysam. I'd like to understand the reasoning behind this—could the author possibly modify this part of the code?