This is WhatsHap 2.8 running under Python 3.9.23
[W::hts_idx_load3] The index file is older than the data file: 1136_8DK-T1-TDNA-1_B23VCL7LT4_1.recalibrated.bam.bai
[W::hts_idx_load3] The index file is older than the data file: 1136_8DK-T1-TDNA-1_B23VCL7LT4_1.recalibrated.bam.bai
[E::idx_find_and_load] Could not retrieve index file for 'input_filtered.vcf.gz'
[E::idx_find_and_load] Could not retrieve index file for 'input_filtered.vcf.gz'
[E::idx_find_and_load] Could not retrieve index file for 'input_filtered.vcf.gz'
Working on 2 samples from 2 families
WARNING: Skipping duplicated position 12811789 on chromosome 'chrY' Hiding further warnings of this type, use --debug to show

# Working on contig chrY in individual 1136_8DK-N1-BDNA-1_B23KFG5LT4_1
Found 0 usable heterozygous variants (0 skipped due to missing genotypes)
WARNING: Sample '1136_8DK-N1-BDNA-1_B23KFG5LT4_1' not found in any BAM/CRAM file.
Found 0 reads covering 0 variants
Kept 0 reads that cover at least two variants each
Selected 0 most phase-informative reads covering 0 variants
Best-case phasing would result in 0 non-singleton phased blocks (0 singletons). 
Phasing 1 sample by solving the MEC problem ...
No. of phased blocks: 0

# Working on contig chrY in individual 1136_8DK-T1-TDNA-1_B23VCL7LT4_1
Found 7 usable heterozygous variants (0 skipped due to missing genotypes)
[W::hts_idx_load3] The index file is older than the data file: 1136_8DK-T1-TDNA-1_B23VCL7LT4_1.recalibrated.bam.bai
Number of supplementary alignments: 0
Number of non-singleton groups: 375
Skipped 0 groups
Found 828 reads covering 7 variants
Kept 0 reads that cover at least two variants each
Selected 0 most phase-informative reads covering 0 variants
Best-case phasing would result in 0 non-singleton phased blocks (0 singletons). 
Phasing 1 sample by solving the MEC problem ...
No. of phased blocks: 0

# Resource usage
Maximum memory usage: 0.193 GB
Time spent reading BAM/CRAM:                    5.9 s
Time spent parsing VCF:                         0.0 s
Time spent selecting reads:                     0.0 s
Time spent phasing:                             0.0 s
Time spent writing VCF:                         0.0 s
Time spent finding components:                  0.0 s
Time spent on rest:                             0.1 s
Total elapsed time:                             6.0 s